Remove trailing commas in enums.

These aren't valid C89. Found thanks to gcc's -Wc90-c99-compat. These
exist in differing places in most supported branches.

src/backend/executor/execIndexing.c

@@ -119,7 +119,7 @@ typedef enum
 {
 	CEOUC_WAIT,
 	CEOUC_NOWAIT,
-	CEOUC_LIVELOCK_PREVENTING_WAIT,
+	CEOUC_LIVELOCK_PREVENTING_WAIT
 } CEOUC_WAIT_MODE;
 
 static bool check_exclusion_or_unique_constraint(Relation heap, Relation index,

src/include/access/xlog_internal.h

@@ -252,7 +252,7 @@ typedef enum
 {
 	RECOVERY_TARGET_ACTION_PAUSE,
 	RECOVERY_TARGET_ACTION_PROMOTE,
-	RECOVERY_TARGET_ACTION_SHUTDOWN,
+	RECOVERY_TARGET_ACTION_SHUTDOWN
 } RecoveryTargetAction;
 
 /*