Ensure consistent sources up to 5.0 where a C++ problem occurs.

client/mysqladmin.c:
  Cast to overcome a C vs. C++ signature problem, occurring in 5.0 where this is a C++ file.

client/mysqladmin.c

@@ -554,7 +554,7 @@ static int execute_commands(MYSQL *mysql,int argc, char **argv)
       {
 	char *pos,buff[40];
 	ulong sec;
-	pos=strchr(status,' ');
+	pos= (char*) strchr(status,' ');
 	*pos++=0;
 	printf("%s\t\t\t",status);			/* print label */
 	if ((status=str2int(pos,10,0,LONG_MAX,(long*) &sec)))