mm/pdflush.c: merge the same code in two path

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/pdflush.c

@@ -207,7 +207,6 @@ int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0)
 
 	spin_lock_irqsave(&pdflush_lock, flags);
 	if (list_empty(&pdflush_list)) {
-		spin_unlock_irqrestore(&pdflush_lock, flags);
 		ret = -1;
 	} else {
 		struct pdflush_work *pdf;
@@ -219,8 +218,9 @@ int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0)
 		pdf->fn = fn;
 		pdf->arg0 = arg0;
 		wake_up_process(pdf->who);
-		spin_unlock_irqrestore(&pdflush_lock, flags);
 	}
+	spin_unlock_irqrestore(&pdflush_lock, flags);
+
 	return ret;
 }