mxqset: Remove unused variable and argument

mxqset.c

@@ -195,7 +195,7 @@ static const struct  argp_option options[] = {
 
 static const struct argp argp = { options, parser, NULL, NULL };
 
-static __attribute__ ((noreturn)) void exit_usage(char *argv0) {
+static __attribute__ ((noreturn)) void exit_usage(void) {
     fprintf(stderr,
 "usage: %s group GID [group-options]\n"
 "\n"
@@ -210,22 +210,20 @@ static __attribute__ ((noreturn)) void exit_usage(char *argv0) {
 }
 
 int main(int argc, char **argv) {
-
-    char *argv0=argv[0];
     struct mx_mysql *mysql = NULL;
     int groupid;
     uid_t uid = getuid();
 
     if (argc<3 || strcmp(argv[1],"group") != 0)
-        exit_usage(argv0);
+        exit_usage();
     groupid=atoi(argv[2]);
 
     int sts;
     struct opts opts={0};
 
     sts=argp_parse (&argp, argc-3, &argv[3], ARGP_PARSE_ARGV0|ARGP_SILENT, NULL, &opts);
     if (sts)
-        exit_usage(argv0);
+        exit_usage();
 
     assert(mx_mysql_initialize(&mysql) == 0);
     mx_mysql_option_set_default_file(mysql, MXQ_MYSQL_DEFAULT_FILE);