ubifs: fix snprintf() checking

The snprintf() function returns the number of characters (not
counting the NUL terminator) that it would have printed if we
had space.

This buffer has UBIFS_DFS_DIR_LEN characters plus one extra for
the terminator.  Printing UBIFS_DFS_DIR_LEN is okay but anything
higher will result in truncation.  Thus the comparison needs to be
change from == to >.

These strings are compile time constants so this patch doesn't
affect runtime.

Fixes: ae380ce ("UBIFS: lessen the size of debugging info data structure")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Alexander Dahl <ada@thorsis.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Author: Dan Carpenter

drivers/mtd/ubi/debug.c

@@ -511,7 +511,7 @@ int ubi_debugfs_init_dev(struct ubi_device *ubi)
 
 	n = snprintf(d->dfs_dir_name, UBI_DFS_DIR_LEN + 1, UBI_DFS_DIR_NAME,
 		     ubi->ubi_num);
-	if (n == UBI_DFS_DIR_LEN) {
+	if (n > UBI_DFS_DIR_LEN) {
 		/* The array size is too small */
 		return -EINVAL;
 	}

fs/ubifs/debug.c

@@ -2824,7 +2824,7 @@ void dbg_debugfs_init_fs(struct ubifs_info *c)
 
 	n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME,
 		     c->vi.ubi_num, c->vi.vol_id);
-	if (n == UBIFS_DFS_DIR_LEN) {
+	if (n > UBIFS_DFS_DIR_LEN) {
 		/* The array size is too small */
 		return;
 	}