plat/arm: Fix ARM_INSTANTIATE_LOCK syntax anomaly

The current definition of ARM_INSTANTIATE_LOCK macro includes a
semicolon, which means it's omitted where it's used. This is anomalous
for a C statement in global scope.

Fix this by removing semicolon from the definition; and where it's a
NOP, declare a file-scoped variable explicitly tagged as unused to avoid
compiler warning.

No functional changes.

Change-Id: I2c1d92ece4777e272a025011e03b8003f3543335
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index 3a73776..f0e9767 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -45,7 +45,7 @@
  * Use this macro to instantiate lock before it is used in below
  * arm_lock_xxx() macros
  */
-#define ARM_INSTANTIATE_LOCK	DEFINE_BAKERY_LOCK(arm_lock);
+#define ARM_INSTANTIATE_LOCK	DEFINE_BAKERY_LOCK(arm_lock)
 #define ARM_LOCK_GET_INSTANCE	(&arm_lock)
 /*
  * These are wrapper macros to the Coherent Memory Bakery Lock API.
@@ -59,7 +59,7 @@
 /*
  * Empty macros for all other BL stages other than BL31 and BL32
  */
-#define ARM_INSTANTIATE_LOCK
+#define ARM_INSTANTIATE_LOCK	static int arm_lock __unused
 #define ARM_LOCK_GET_INSTANCE	0
 #define arm_lock_init()
 #define arm_lock_get()