fix: remove parentIsObject() check (#12851)

we will allow situations such as

```
a/b/1.txt
a/b
```

and

```
a/b
a/b/1.txt
```

we are going to document that this usecase is
not supported and we will never support it, if
any application does this users have to delete
the top level parent to make sure namespace is
accessible at lower level.

rest of the situations where the prefixes get
created across sets are supported as is.

cmd/erasure-common.go

@@ -20,8 +20,6 @@ package cmd
 import (
 	"context"
 	"sync"
-
-	"github.com/minio/minio/internal/sync/errgroup"
 )
 
 func (er erasureObjects) getLocalDisks() (localDisks []StorageAPI) {
@@ -101,34 +99,3 @@ func (er erasureObjects) getLoadBalancedDisks(optimized bool) []StorageAPI {
 	// Return disks which have maximum disk usage common.
 	return newDisks[max]
 }
-
-// This function does the following check, suppose
-// object is "a/b/c/d", stat makes sure that objects
-// - "a/b/c"
-// - "a/b"
-// - "a"
-// do not exist on the namespace.
-func (er erasureObjects) parentDirIsObject(ctx context.Context, bucket, parent string) bool {
-	storageDisks := er.getDisks()
-
-	g := errgroup.WithNErrs(len(storageDisks))
-
-	for index := range storageDisks {
-		index := index
-		g.Go(func() error {
-			if storageDisks[index] == nil {
-				return errDiskNotFound
-			}
-			// Check if 'prefix' is an object on this 'disk', else continue the check the next disk
-			return storageDisks[index].CheckFile(ctx, bucket, parent)
-		}, index)
-	}
-
-	// NOTE: Observe we are not trying to read `xl.meta` and figure out the actual
-	// quorum intentionally, but rely on the default case scenario. Actual quorum
-	// verification will happen by top layer by using getObjectInfo() and will be
-	// ignored if necessary.
-	readQuorum := getReadQuorum(len(storageDisks))
-
-	return reduceReadQuorumErrs(ctx, g.Wait(), objectOpIgnoredErrs, readQuorum) == nil
-}