usrloc: Fix some incorrect startup checks

On some misconfigured scripts (e.g. DB usrloc + db_url modparam, but
without any SQL DB module loaded), the module would report some strange
errors, instead of the more intuitive:

WARNING:core:solve_module_dependencies: module usrloc depends on an
 sqldb module due to modparam working_mode_preset, but none was loaded!
ERROR:core:main: failed to solve module dependencies

Thanks to Vlad Pătrașcu for the catch!

(cherry picked from commit 0b55ca3)

modules/usrloc/ul_mod.c

@@ -300,7 +300,7 @@ static module_dependency_t *get_deps_db_mode(param_export_t *param)
 
 static module_dependency_t *get_deps_wmode_preset(param_export_t *param)
 {
-	char *haystack = (char *)param->param_pointer;
+	char *haystack = *(char **)param->param_pointer;
 
 	if (l_memmem(haystack, "sql-", strlen(haystack), strlen("sql-")))
 		return alloc_module_dep(MOD_TYPE_SQLDB, NULL, DEP_ABORT);
@@ -313,7 +313,7 @@ static module_dependency_t *get_deps_wmode_preset(param_export_t *param)
 
 static module_dependency_t *get_deps_rr_persist(param_export_t *param)
 {
-	if (!strcasecmp((char *)param->param_pointer, "load-from-sql"))
+	if (!strcasecmp(*(char **)param->param_pointer, "load-from-sql"))
 		return alloc_module_dep(MOD_TYPE_SQLDB, NULL, DEP_ABORT);
 
 	return NULL;