Fix MISRA Rule 5.3 Part 2

Use a _ prefix for Macro arguments to prevent that argument from
hiding variables of the same name in the outer scope

Rule 5.3: An identifier declared in an inner scope shall not
          hide an identifier declared in an outer scope

Fixed For:
    make LOG_LEVEL=50 PLAT=fvp

Change-Id: I67b6b05cbad4aeca65ce52981b4679b340604708
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>
diff --git a/lib/locks/bakery/bakery_lock_coherent.c b/lib/locks/bakery/bakery_lock_coherent.c
index a857e03..788ba98 100644
--- a/lib/locks/bakery/bakery_lock_coherent.c
+++ b/lib/locks/bakery/bakery_lock_coherent.c
@@ -34,9 +34,9 @@
  * accesses regardless of status of address translation.
  */
 
-#define assert_bakery_entry_valid(entry, bakery) do {	\
-	assert(bakery);					\
-	assert(entry < BAKERY_LOCK_MAX_CPUS);		\
+#define assert_bakery_entry_valid(_entry, _bakery) do {	\
+	assert(_bakery);					\
+	assert(_entry < BAKERY_LOCK_MAX_CPUS);		\
 } while (0)
 
 /* Obtain a ticket for a given CPU */