test: keep the example client releases reachable

gocritic's exitAfterDefer failed the lint job on the two examples this
branch gave a `defer func() { _ = client.Close() }()`. log.Fatalf calls
os.Exit, which does not unwind the stack, so every Fatalf placed after the
defer would have skipped the close the branch added -- the leak the branch
set out to fix, still leaking on the error path.

Switch those calls to log.Panicf, which runs deferred functions on its way
out. Examples have no *testing.T, so require.NoError and t.Cleanup are not
available here; panicking is what the neighbouring osprom and osotel
examples already do.

Signed-off-by: Sean Chittenden <sean.chittenden@crowdstrike.com>

Author: sean-

opensearch_example_test.go

@@ -56,7 +56,7 @@ func ExampleNewDefaultClient() {
 
 	_, err = client.Info(ctx, nil)
 	if err != nil {
-		log.Fatalf("Error getting the response: %s\n", err)
+		log.Panicf("Error getting the response: %s\n", err)
 	}
 
 	log.Print(client.Client.Transport.(*opensearchtransport.Transport).URLs())

opensearchutil/bulk_indexer_example_test.go

@@ -75,7 +75,7 @@ func ExampleNewBulkIndexer() {
 		FlushBytes: 5e+6,       // The flush threshold in bytes (default: 5M)
 	})
 	if err != nil {
-		log.Fatalf("Error creating the indexer: %s", err)
+		log.Panicf("Error creating the indexer: %s", err)
 	}
 
 	// Add an item to the indexer
@@ -116,20 +116,20 @@ func ExampleNewBulkIndexer() {
 		},
 	)
 	if err != nil {
-		log.Fatalf("Unexpected error: %s", err)
+		log.Panicf("Unexpected error: %s", err)
 	}
 
 	// Close the indexer channel and flush remaining items
 	//
 	if err := indexer.Close(context.Background()); err != nil {
-		log.Fatalf("Unexpected error: %s", err)
+		log.Panicf("Unexpected error: %s", err)
 	}
 
 	// Report the indexer statistics
 	//
 	stats := indexer.Stats()
 	if stats.NumFailed > 0 {
-		log.Fatalf("Indexed [%d] documents with [%d] errors", stats.NumFlushed, stats.NumFailed)
+		log.Panicf("Indexed [%d] documents with [%d] errors", stats.NumFlushed, stats.NumFailed)
 	}
 	log.Printf("Successfully indexed [%d] documents", stats.NumFlushed)