fix: failpoint-toolexec not working on Windows (#90)

On Windows, the compile command is never detected because
`strings.TrimSuffix(goCmd, ".exe")` operates on the full path
(e.g. `C:\...\compile.exe` → `C:\...\compile`) instead of the
base name. The comparison `goCmdBase == "compile"` always fails.

Fix: use `goCmdBase` instead of `goCmd` in TrimSuffix.

Author: hulucc

failpoint-toolexec/main.go

@@ -37,7 +37,7 @@ func main() {
 	goCmd, buildArgs := os.Args[1], os.Args[2:]
 	goCmdBase := filepath.Base(goCmd)
 	if runtime.GOOS == "windows" {
-		goCmdBase = strings.TrimSuffix(goCmd, ".exe")
+		goCmdBase = strings.TrimSuffix(goCmdBase, ".exe")
 	}
 
 	if strings.ToLower(goCmdBase) == "compile" {