m68k: hp300 core - Kill warn_unused_result warnings

warning: ignoring return value of 'request_irq', declared with attribute
warn_unused_result
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/hp300/time.c

@@ -70,7 +70,8 @@ void __init hp300_sched_init(irq_handler_t vector)
 
   asm volatile(" movpw %0,%1@(5)" : : "d" (INTVAL), "a" (CLOCKBASE));
 
-  request_irq(IRQ_AUTO_6, hp300_tick, IRQ_FLG_STD, "timer tick", vector);
+  if (request_irq(IRQ_AUTO_6, hp300_tick, IRQ_FLG_STD, "timer tick", vector))
+    pr_err("Couldn't register timer interrupt\n");
 
   out_8(CLOCKBASE + CLKCR2, 0x1);		/* select CR1 */
   out_8(CLOCKBASE + CLKCR1, 0x40);		/* enable irq */