plat: fix switch statements to comply with MISRA rules

Ensure (where possible) that switch statements in plat comply with MISRA
rules 16.1 - 16.7.

Change-Id: Ie4a7d2fd10f6141c0cfb89317ea28a755391622f
Signed-off-by: Jonathan Wright <jonathan.wright@arm.com>
diff --git a/plat/arm/board/fvp/fvp_pm.c b/plat/arm/board/fvp/fvp_pm.c
index f61cdb3..0fa83a5 100644
--- a/plat/arm/board/fvp/fvp_pm.c
+++ b/plat/arm/board/fvp/fvp_pm.c
@@ -324,13 +324,11 @@
 	if (psysr == PSYSR_INVALID)
 		return PSCI_E_INVALID_PARAMS;
 
-	switch (power_level) {
-	case ARM_PWR_LVL0:
+	if (power_level == ARM_PWR_LVL0) {
 		ret = (psysr & PSYSR_AFF_L0) ? HW_ON : HW_OFF;
-		break;
-	case ARM_PWR_LVL1:
+	} else {
+		/* power_level == ARM_PWR_LVL1 */
 		ret = (psysr & PSYSR_AFF_L1) ? HW_ON : HW_OFF;
-		break;
 	}
 
 	return ret;