Restore return statement in kernel-as3525.c that was accidentally removed in r26330. This fixes c200v2 black screen.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26361 a1c6a512-1295-4272-9138-f99709370657

firmware/target/arm/as3525/kernel-as3525.c

@@ -111,6 +111,7 @@ static inline void do_sw_pwm(void)
 {
     if (!timer2_pwm_on) {
         do_scrollwheel();  /* Handle scrollwheel and tick tasks */
+        return;
     }
 
     timer2_pwm_state ^= 1;