UBIFS: correct usage of IS_ENABLED()

Commit "818039c UBIFS: fix debugfs-less systems support" fixed one
regression but introduced a different regression - the debugfs is now always
compiled out. Root cause: IS_ENABLED() arguments should be used with the
CONFIG_* prefix.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

fs/ubifs/debug.c

@@ -2918,7 +2918,7 @@ int dbg_debugfs_init_fs(struct ubifs_info *c)
 	struct dentry *dent;
 	struct ubifs_debug_info *d = c->dbg;
 
-	if (!IS_ENABLED(DEBUG_FS))
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
 		return 0;
 
 	n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME,
@@ -3013,7 +3013,7 @@ int dbg_debugfs_init_fs(struct ubifs_info *c)
  */
 void dbg_debugfs_exit_fs(struct ubifs_info *c)
 {
-	if (IS_ENABLED(DEBUG_FS))
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
 		debugfs_remove_recursive(c->dbg->dfs_dir);
 }
 
@@ -3099,7 +3099,7 @@ int dbg_debugfs_init(void)
 	const char *fname;
 	struct dentry *dent;
 
-	if (!IS_ENABLED(DEBUG_FS))
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
 		return 0;
 
 	fname = "ubifs";
@@ -3166,7 +3166,7 @@ int dbg_debugfs_init(void)
  */
 void dbg_debugfs_exit(void)
 {
-	if (IS_ENABLED(DEBUG_FS))
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
 		debugfs_remove_recursive(dfs_rootdir);
 }