sh: Handle -ERESTART_RESTARTBLOCK for restartable syscalls.

The current implementation only handles -ERESTARTNOHAND, whereas we
also need to handle -ERESTART_RESTARTBLOCK in the handle_signal()
case for restartable system calls.

As noted by Carl:

This fixes the LTP test nanosleep03 - the current kernel causes
-ERESTART_RESTARTBLOCK to reach user space rather than the correct
-EINTR.

Reported-by: Carl Shaw <shaw.carl@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/signal.c

@@ -489,6 +489,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 	if (regs->tra >= 0) {
 		/* If so, check system call restarting.. */
 		switch (regs->regs[0]) {
+			case -ERESTART_RESTARTBLOCK:
 			case -ERESTARTNOHAND:
 				regs->regs[0] = -EINTR;
 				break;
@@ -584,8 +585,8 @@ static void do_signal(struct pt_regs *regs, unsigned int save_r0)
 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 	if (signr > 0) {
 		/* Whee!  Actually deliver the signal.  */
-		if (handle_signal(signr, &ka, &info, oldset, regs, save_r0)
-		    == 0) {
+		if (handle_signal(signr, &ka, &info, oldset,
+				  regs, save_r0) == 0) {
 			/* a signal was successfully delivered; the saved
 			 * sigmask will have been stored in the signal frame,
 			 * and will be restored by sigreturn, so we can simply