mm/vmstat.c: remove debug fs entries on failure of file creation and made extfrag_debug_root dentry local

Remove debug fs files and directory on failure.  Since no one is using
"extfrag_debug_root" dentry outside of extfrag_debug_init(), make it
local to the function.

Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmstat.c

@@ -1223,7 +1223,6 @@ module_init(setup_vmstat)
 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
 #include <linux/debugfs.h>
 
-static struct dentry *extfrag_debug_root;
 
 /*
  * Return an index indicating how much of the available free memory is
@@ -1361,19 +1360,24 @@ static const struct file_operations extfrag_file_ops = {
 
 static int __init extfrag_debug_init(void)
 {
+	struct dentry *extfrag_debug_root;
+
 	extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
 	if (!extfrag_debug_root)
 		return -ENOMEM;
 
 	if (!debugfs_create_file("unusable_index", 0444,
 			extfrag_debug_root, NULL, &unusable_file_ops))
-		return -ENOMEM;
+		goto fail;
 
 	if (!debugfs_create_file("extfrag_index", 0444,
 			extfrag_debug_root, NULL, &extfrag_file_ops))
-		return -ENOMEM;
+		goto fail;
 
 	return 0;
+fail:
+	debugfs_remove_recursive(extfrag_debug_root);
+	return -ENOMEM;
 }
 
 module_init(extfrag_debug_init);