proc: enclose desc variable of show_stat() in CONFIG_SPARSE_IRQ

Impact: restructure code to fix compiler warning

commit 240d367b moved desc usage point
into #ifdef CONFIG_SPARSE_IRQ.

Eliminate the desc variable, otherwise following warning happens:

 fs/proc/stat.c: In function 'show_stat':
 fs/proc/stat.c:31: warning: unused variable 'desc'

[ akpm: cleaned up the patch to remove #ifdef ]
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

fs/proc/stat.c

@@ -27,7 +27,6 @@ static int show_stat(struct seq_file *p, void *v)
 	u64 sum = 0;
 	struct timespec boottime;
 	unsigned int per_irq_sum;
-	struct irq_desc *desc;
 
 	user = nice = system = idle = iowait =
 		irq = softirq = steal = cputime64_zero;
@@ -47,8 +46,7 @@ static int show_stat(struct seq_file *p, void *v)
 		guest = cputime64_add(guest, kstat_cpu(i).cpustat.guest);
 		for_each_irq_nr(j) {
 #ifdef CONFIG_SPARSE_IRQ
-			desc = irq_to_desc(j);
-			if (!desc)
+			if (!irq_to_desc(j))
 				continue;
 #endif
 			sum += kstat_irqs_cpu(j, i);
@@ -98,8 +96,7 @@ static int show_stat(struct seq_file *p, void *v)
 	for_each_irq_nr(j) {
 		per_irq_sum = 0;
 #ifdef CONFIG_SPARSE_IRQ
-		desc = irq_to_desc(j);
-		if (!desc) {
+		if (!irq_to_desc(j)) {
 			seq_printf(p, " %u", per_irq_sum);
 			continue;
 		}