UBIFS: suppress compilation warning

Fix "using uninitialized variable" compilation warning by using
the "unititialized_var()" helper.

Signed-off-by: Subrata Modak<subrata@linux.vnet.ibm.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

fs/ubifs/commit.c

@@ -510,7 +510,7 @@ int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
 	int lnum, offs, len, err = 0, uninitialized_var(last_level), child_cnt;
 	int first = 1, iip;
 	struct ubifs_debug_info *d = c->dbg;
-	union ubifs_key lower_key, upper_key, l_key, u_key;
+	union ubifs_key uninitialized_var(lower_key), upper_key, l_key, u_key;
 	unsigned long long uninitialized_var(last_sqnum);
 	struct ubifs_idx_node *idx;
 	struct list_head list;