Btrfs: check error before reporting missing device and add uuid

Report missing device when add is successful,
otherwise it would exit as ENOMEM. And add uuid
to the report.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

fs/btrfs/volumes.c

@@ -6230,10 +6230,11 @@ static int read_one_dev(struct btrfs_root *root,
 		if (!btrfs_test_opt(root, DEGRADED))
 			return -EIO;
 
-		btrfs_warn(root->fs_info, "devid %llu missing", devid);
 		device = add_missing_dev(root, fs_devices, devid, dev_uuid);
 		if (!device)
 			return -ENOMEM;
+		btrfs_warn(root->fs_info, "devid %llu uuid %pU missing",
+				devid, dev_uuid);
 	} else {
 		if (!device->bdev && !btrfs_test_opt(root, DEGRADED))
 			return -EIO;