signal: Replace memset(info,...) with clear_siginfo for clarity

The function clear_siginfo is just a nice wrapper around memset so
this results in no functional change.  This change makes mistakes
a little more difficult and it makes it clearer what is going on.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

arch/um/kernel/trap.c

@@ -306,7 +306,7 @@ void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
 
 	arch_examine_signal(sig, regs);
 
-	memset(&clean_si, 0, sizeof(clean_si));
+	clear_siginfo(&clean_si);
 	clean_si.si_signo = si->si_signo;
 	clean_si.si_errno = si->si_errno;
 	clean_si.si_code = si->si_code;

drivers/usb/core/devio.c

@@ -595,7 +595,7 @@ static void async_completed(struct urb *urb)
 	as->status = urb->status;
 	signr = as->signr;
 	if (signr) {
-		memset(&sinfo, 0, sizeof(sinfo));
+		clear_siginfo(&sinfo);
 		sinfo.si_signo = as->signr;
 		sinfo.si_errno = as->status;
 		sinfo.si_code = SI_ASYNCIO;
@@ -2613,7 +2613,7 @@ static void usbdev_remove(struct usb_device *udev)
 		wake_up_all(&ps->wait);
 		list_del_init(&ps->list);
 		if (ps->discsignr) {
-			memset(&sinfo, 0, sizeof(sinfo));
+			clear_siginfo(&sinfo);
 			sinfo.si_signo = ps->discsignr;
 			sinfo.si_errno = EPIPE;
 			sinfo.si_code = SI_ASYNCIO;

kernel/seccomp.c

@@ -515,7 +515,7 @@ void put_seccomp_filter(struct task_struct *tsk)
 
 static void seccomp_init_siginfo(siginfo_t *info, int syscall, int reason)
 {
-	memset(info, 0, sizeof(*info));
+	clear_siginfo(info);
 	info->si_signo = SIGSYS;
 	info->si_code = SYS_SECCOMP;
 	info->si_call_addr = (void __user *)KSTK_EIP(current);

kernel/time/posix-timers.c

@@ -462,7 +462,7 @@ static struct k_itimer * alloc_posix_timer(void)
 		kmem_cache_free(posix_timers_cache, tmr);
 		return NULL;
 	}
-	memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
+	clear_siginfo(&tmr->sigq->info);
 	return tmr;
 }