[POWERPC] Remove warning in mpic.c

arch/powerpc/sysdev/mpic.c: In function 'mpic_request_ipis':
arch/powerpc/sysdev/mpic.c:1445: warning: ignoring return value of 'request_irq', declared with attribute warn_unused_result

Signed-off-by: Olof Johansson <[e-mail]>
Signed-off-by: Paul Mackerras <[e-mail]>

arch/powerpc/sysdev/mpic.c

···
 void mpic_request_ipis(void)
 {
 	struct mpic *mpic = mpic_primary;
-	int i;
+	int i, err;
 	static char *ipi_names[] = {
 		"IPI0 (call function)",
 		"IPI1 (reschedule)",
···
 			printk(KERN_ERR "Failed to map IPI %d\n", i);
 			break;
 		}
-		request_irq(vipi, mpic_ipi_action, IRQF_DISABLED|IRQF_PERCPU,
-			    ipi_names[i], mpic);
+		err = request_irq(vipi, mpic_ipi_action,
+				  IRQF_DISABLED|IRQF_PERCPU,
+				  ipi_names[i], mpic);
+		if (err) {
+			printk(KERN_ERR "Request of irq %d for IPI %d failed\n",
+			       vipi, i);
+			break;
+		}
 	}
 }