Fix MISRA defects in workaround and errata framework

No functional changes.

Change-Id: Iaab0310848be587b635ce5339726e92a50f534e0
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/lib/cpus/aarch64/cortex_a75_pubsub.c b/lib/cpus/aarch64/cortex_a75_pubsub.c
index 16f62f4..f4ca486 100644
--- a/lib/cpus/aarch64/cortex_a75_pubsub.c
+++ b/lib/cpus/aarch64/cortex_a75_pubsub.c
@@ -12,14 +12,16 @@
 {
 	if (midr_match(CORTEX_A75_MIDR) != 0)
 		cpuamu_context_save(CORTEX_A75_AMU_NR_COUNTERS);
-	return 0;
+
+	return (void *)0;
 }
 
 static void *cortex_a75_context_restore(const void *arg)
 {
 	if (midr_match(CORTEX_A75_MIDR) != 0)
 		cpuamu_context_restore(CORTEX_A75_AMU_NR_COUNTERS);
-	return 0;
+
+	return (void *)0;
 }
 
 SUBSCRIBE_TO_EVENT(psci_suspend_pwrdown_start, cortex_a75_context_save);