Flashy workaround for GTT S356523

Summary: S356523 - checks and remediations are failing for any gtt running v2023.25.2 and above

Test Plan:
```
$ go test .
ok      github.com/facebook/openbmc/tools/flashy/checks_and_remediations/common
```

Will look to build flashy ASAP and test against a previously failed host

Reviewed By: lsiudut

Differential Revision: D47928352

fbshipit-source-id: 2d654d4476d4ba15307a88d563c4d54b34b9ca7c

Author: cjcon90

tools/flashy/checks_and_remediations/common/05_ensure_flash_writable.go

@@ -59,8 +59,19 @@ func ensureFlashWritable(stepParams step.StepParams) step.StepExitError {
 		return nil
 	}
 
+	// S356523 workaround:
+	// grandteton v2023.25.2 introduced an error whereby mtd0 was set as spi0.1
+	// this breaks checks and remediations as it thinks flash1 is read-only
+	// let's put in a workaround so we can upgrade all the affected hosts
+	cmd := []string{"grep", "mtd0:.*spi0.1 /proc/mtd"}
+	_, _, stdout, _ := utils.RunCommand(cmd, 30*time.Second)
+	if strings.Contains(stdout, "mtd0") {
+		log.Printf("Skipping ensure_flash_writable check for this device due to S356523")
+		return nil
+	}
+
 	// First up check that fw_printenv works okay and produces output.
-	cmd := []string{"fw_printenv", "bootargs"}
+	cmd = []string{"fw_printenv", "bootargs"}
 	_, err, stdout, stderr := utils.RunCommand(cmd, 30*time.Second)
 	if err != nil || !strings.Contains(stdout, "bootargs") {
 		log.Printf("fw_printenv doesn't work: %v, stderr: %v", err, stderr)

tools/flashy/checks_and_remediations/common/05_ensure_flash_writable_test.go

@@ -48,6 +48,7 @@ func TestEnsureFlashWritable(t *testing.T) {
 	cases := []struct {
 		name              string
 		vbootUtilExists   bool
+		s356523						string
 		failPrint         bool
 		failSet           bool
 		failCheck         bool
@@ -57,6 +58,7 @@ func TestEnsureFlashWritable(t *testing.T) {
 		{
 			name:              "non-vboot case",
 			vbootUtilExists:   false,
+			s356523:					 "",
 			failPrint:         false,
 			failSet:           false,
 			failCheck:         false,
@@ -66,6 +68,17 @@ func TestEnsureFlashWritable(t *testing.T) {
 		{
 			name:              "working case",
 			vbootUtilExists:   true,
+			s356523:					 "",
+			failPrint:         false,
+			failSet:           false,
+			failCheck:         false,
+			failClear:         false,
+			want:              nil,
+		},
+		{
+			name:              "s356523 case",
+			vbootUtilExists:   true,
+			s356523:					 "mtd0: 08000000 00010000 \"spi0.1\"",
 			failPrint:         false,
 			failSet:           false,
 			failCheck:         false,
@@ -75,6 +88,7 @@ func TestEnsureFlashWritable(t *testing.T) {
 		{
 			name:              "fw_printenv broken",
 			vbootUtilExists:   true,
+			s356523:					 "",
 			failPrint:         true,
 			failSet:           false,
 			failCheck:         false,
@@ -84,6 +98,7 @@ func TestEnsureFlashWritable(t *testing.T) {
 		{
 			name:              "set _flashy_test fails",
 			vbootUtilExists:   true,
+			s356523:					 "",
 			failPrint:         false,
 			failSet:           true,
 			failCheck:         false,
@@ -93,6 +108,7 @@ func TestEnsureFlashWritable(t *testing.T) {
 		{
 			name:              "check _flashy_test fails",
 			vbootUtilExists:   true,
+			s356523:					 "",
 			failPrint:         false,
 			failSet:           false,
 			failCheck:         true,
@@ -103,6 +119,7 @@ func TestEnsureFlashWritable(t *testing.T) {
 		{
 			name:              "clear _flashy_test fails",
 			vbootUtilExists:   true,
+			s356523:					 "",
 			failPrint:         false,
 			failSet:           false,
 			failCheck:         false,
@@ -141,7 +158,11 @@ func TestEnsureFlashWritable(t *testing.T) {
 						} else {
 							return 0, nil, "bootargs=foo", ""
 						}
-					} else {
+					} else if (cmdArr[0] == "grep") {
+						if (cmdArr[1] == "mtd0:.*spi0.1 /proc/mtd") {
+							return 0, nil, tc.s356523, ""
+						}
+					} else{
 						if (tc.failSet) {
 							return 0, errors.Errorf("err2"), "", "err2"
 						} else {