posix-timers: fix shadowed variables

Fix sparse warnings like this:
kernel/posix-cpu-timers.c:1090:25: warning: symbol 't' shadows an earlier one
kernel/posix-cpu-timers.c:1058:21: originally declared here
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/posix-cpu-timers.c

@@ -1087,45 +1087,45 @@ static void check_process_timers(struct task_struct *tsk,
 	maxfire = 20;
 	prof_expires = cputime_zero;
 	while (!list_empty(timers)) {
-		struct cpu_timer_list *t = list_first_entry(timers,
+		struct cpu_timer_list *tl = list_first_entry(timers,
 						      struct cpu_timer_list,
 						      entry);
-		if (!--maxfire || cputime_lt(ptime, t->expires.cpu)) {
-			prof_expires = t->expires.cpu;
+		if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) {
+			prof_expires = tl->expires.cpu;
 			break;
 		}
-		t->firing = 1;
-		list_move_tail(&t->entry, firing);
+		tl->firing = 1;
+		list_move_tail(&tl->entry, firing);
 	}
 
 	++timers;
 	maxfire = 20;
 	virt_expires = cputime_zero;
 	while (!list_empty(timers)) {
-		struct cpu_timer_list *t = list_first_entry(timers,
+		struct cpu_timer_list *tl = list_first_entry(timers,
 						      struct cpu_timer_list,
 						      entry);
-		if (!--maxfire || cputime_lt(utime, t->expires.cpu)) {
-			virt_expires = t->expires.cpu;
+		if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) {
+			virt_expires = tl->expires.cpu;
 			break;
 		}
-		t->firing = 1;
-		list_move_tail(&t->entry, firing);
+		tl->firing = 1;
+		list_move_tail(&tl->entry, firing);
 	}
 
 	++timers;
 	maxfire = 20;
 	sched_expires = 0;
 	while (!list_empty(timers)) {
-		struct cpu_timer_list *t = list_first_entry(timers,
+		struct cpu_timer_list *tl = list_first_entry(timers,
 						      struct cpu_timer_list,
 						      entry);
-		if (!--maxfire || sum_sched_runtime < t->expires.sched) {
-			sched_expires = t->expires.sched;
+		if (!--maxfire || sum_sched_runtime < tl->expires.sched) {
+			sched_expires = tl->expires.sched;
 			break;
 		}
-		t->firing = 1;
-		list_move_tail(&t->entry, firing);
+		tl->firing = 1;
+		list_move_tail(&tl->entry, firing);
 	}
 
 	/*