btrfs: btrfs_bio_clone never fails, skip error handling

Update direct callers of btrfs_bio_clone that do error handling, that we
can now remove.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -8584,10 +8584,6 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
 	skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
 
 	bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
-	if (!bio) {
-		ret = -ENOMEM;
-		goto free_ordered;
-	}
 
 	dip = kzalloc(sizeof(*dip), GFP_NOFS);
 	if (!dip) {

fs/btrfs/volumes.c

@@ -6255,10 +6255,9 @@ int btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 			continue;
 		}
 
-		if (dev_nr < total_devs - 1) {
+		if (dev_nr < total_devs - 1)
 			bio = btrfs_bio_clone(first_bio, GFP_NOFS);
-			BUG_ON(!bio); /* -ENOMEM */
-		} else
+		else
 			bio = first_bio;
 
 		submit_stripe_bio(bbio, bio, bbio->stripes[dev_nr].physical,