signal/powerpc: Simplify _exception_pkey by using force_sig_pkuerr

Call force_sig_pkuerr directly instead of rolling it by hand
in _exception_pkey.
Reviewed-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

arch/powerpc/kernel/traps.c

@@ -364,18 +364,10 @@ static bool exception_common(int signr, struct pt_regs *regs, int code,
 
 void _exception_pkey(struct pt_regs *regs, unsigned long addr, int key)
 {
-	siginfo_t info;
-
 	if (!exception_common(SIGSEGV, regs, SEGV_PKUERR, addr))
 		return;
 
-	clear_siginfo(&info);
-	info.si_signo = SIGSEGV;
-	info.si_code = SEGV_PKUERR;
-	info.si_addr = (void __user *) addr;
-	info.si_pkey = key;
-
-	force_sig_info(info.si_signo, &info, current);
+	force_sig_pkuerr((void __user *) addr, key);
 }
 
 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)