signal/nds32: Use force_sig(SIGILL) in do_revisn

As originally committed do_revisn would deliver a siginfo for SIGILL
with an si_code composed of random stack contents.  That makes no
sense and is not something userspace can depend on.  So simplify
the code and just use "force_sig(SIG_ILL, current)" instead.

Fixes: 2923f5ea77 ("nds32: Exception handling")
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

arch/nds32/kernel/traps.c

@@ -356,14 +356,11 @@ void do_dispatch_tlb_misc(unsigned long entry, unsigned long addr,
 
 void do_revinsn(struct pt_regs *regs)
 {
-	siginfo_t si;
 	pr_emerg("Reserved Instruction\n");
 	show_regs(regs);
 	if (!user_mode(regs))
 		do_exit(SIGILL);
-	si.si_signo = SIGILL;
-	si.si_errno = 0;
-	force_sig_info(SIGILL, &si, current);
+	force_sig(SIGILL, current);
 }
 
 #ifdef CONFIG_ALIGNMENT_TRAP