c6x: ->restart_block.fn needs to be reset on rt_sigreturn

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

arch/c6x/kernel/signal.c

@@ -69,6 +69,9 @@ asmlinkage int do_rt_sigreturn(struct pt_regs *regs)
 	struct rt_sigframe __user *frame;
 	sigset_t set;
 
+	/* Always make any pending restarted system calls return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
 	/*
 	 * Since we stacked the signal on a dword boundary,
 	 * 'sp' should be dword aligned here.  If it's