Btrfs: Use current_fsuid/gid

This fixes compile problems with linux-next
Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/inode.c

@@ -3422,8 +3422,8 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	if (objectid > root->highest_inode)
 		root->highest_inode = objectid;
 
-	inode->i_uid = current->fsuid;
-	inode->i_gid = current->fsgid;
+	inode->i_uid = current_fsuid();
+	inode->i_gid = current_fsgid();
 	inode->i_mode = mode;
 	inode->i_ino = objectid;
 	inode_set_bytes(inode, 0);