sh64: 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. Follows the sh change.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh64/kernel/signal.c

@@ -640,6 +640,7 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 	if (regs->syscall_nr >= 0) {
 		/* If so, check system call restarting.. */
 		switch (regs->regs[REG_RET]) {
+			case -ERESTART_RESTARTBLOCK:
 			case -ERESTARTNOHAND:
 				regs->regs[REG_RET] = -EINTR;
 				break;