ext4: Fix null bh pointer dereference in mballoc

Repoted by Adrian Bunk <[e-mail]>:

The Coverity checker spotted the following NULL dereference:

static int ext4_mb_mark_diskspace_used
{
...
if (!bitmap_bh)
goto out_err;
...
out_err:
sb->s_dirt = 1;
put_bh(bitmap_bh);
...

Signed-off-by: Aneesh Kumar K.V <[e-mail]>
Signed-off-by: Mingming Cao <[e-mail]>

fs/ext4/mballoc.c

···
 
 out_err:
 	sb->s_dirt = 1;
-	put_bh(bitmap_bh);
+	brelse(bitmap_bh);
 	return err;
 }