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/access/transam/xlog.c

@@ -552,7 +552,7 @@ typedef enum
 	XLOG_FROM_ANY = 0,			/* request to read WAL from any source */
 	XLOG_FROM_ARCHIVE,			/* restored using restore_command */
 	XLOG_FROM_PG_XLOG,			/* existing file in pg_xlog */
-	XLOG_FROM_STREAM,			/* streamed from master */
+	XLOG_FROM_STREAM			/* streamed from master */
 } XLogSource;
 
 /* human-readable names for XLogSources, for debugging output */

src/include/catalog/objectaccess.h

@@ -45,7 +45,7 @@ typedef enum ObjectAccessType
 	OAT_DROP,
 	OAT_POST_ALTER,
 	OAT_NAMESPACE_SEARCH,
-	OAT_FUNCTION_EXECUTE,
+	OAT_FUNCTION_EXECUTE
 } ObjectAccessType;
 
 /*

src/include/pgstat.h

@@ -640,7 +640,7 @@ typedef enum BackendState
 	STATE_IDLEINTRANSACTION,
 	STATE_FASTPATH,
 	STATE_IDLEINTRANSACTION_ABORTED,
-	STATE_DISABLED,
+	STATE_DISABLED
 } BackendState;
 
 /* ----------

src/include/utils/jsonapi.h

@@ -30,7 +30,7 @@ typedef enum
 	JSON_TOKEN_TRUE,
 	JSON_TOKEN_FALSE,
 	JSON_TOKEN_NULL,
-	JSON_TOKEN_END,
+	JSON_TOKEN_END
 } JsonTokenType;