[XFS] Fix sendfile return code to be ssize_t in all places.

SGI Modid: xfs-linux:xfs-kern:172110a

fs/xfs/linux/xfs_file.c

@@ -261,10 +261,10 @@ linvfs_sendfile(
 	void			*target)
 {
 	vnode_t			*vp = LINVFS_GET_VP(filp->f_dentry->d_inode);
-	int			error;
+	ssize_t			rval;
 
-	VOP_SENDFILE(vp, filp, ppos, 0, count, actor, target, NULL, error);
-	return error;
+	VOP_SENDFILE(vp, filp, ppos, 0, count, actor, target, NULL, rval);
+	return rval;
 }