HV: x86: fix "Procedure has more than one exit point"

IEC 61508, ISO 26262 standards highly recommand single-exit rule.

Tracked-On: #861
Signed-off-by: Kaige Fu <kaige.fu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/arch/x86/ioapic.c

@@ -262,13 +262,15 @@ uint8_t irq_to_pin(uint32_t irq)
 uint32_t pin_to_irq(uint8_t pin)
 {
 	uint32_t i;
+	uint32_t irq = IRQ_INVALID;
 
 	for (i = 0U; i < nr_gsi; i++) {
 		if (gsi_table[i].pin == pin) {
-			return i;
+			irq = i;
+			break;
 		}
 	}
-	return IRQ_INVALID;
+	return irq;
 }
 
 static void