Corrected a syntax error detected in test build.

client/mysqltest.c:
  Syntax error: Removed the trailing comma after last element of an "enum" list.

client/mysqltest.c

@@ -284,7 +284,7 @@ Q_EXIT,
 
 Q_UNKNOWN,			       /* Unknown command.   */
 Q_COMMENT,			       /* Comments, ignored. */
-Q_COMMENT_WITH_COMMAND,
+Q_COMMENT_WITH_COMMAND
 };
 
 /* this should really be called command */