microblaze: ->restart_block.fn needs to be reset on rt_sigreturn

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

arch/microblaze/kernel/signal.c

@@ -98,6 +98,9 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
 	sigset_t set;
 	int rval;
 
+	/* Always make any pending restarted system calls return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 		goto badframe;