sysv-generator: don't check first if hashmap contains the service name

Just test if hashmap_get returns null. hashmap_contains does exactly
same thing internally so this is slightly more efficient for the true
case.

Silences a coverity warning too. CID#1237648

src/sysv-generator/sysv-generator.c

@@ -810,9 +810,8 @@ static int set_dependencies_from_rcnd(LookupPaths lp, Hashmap *all_services) {
                                         goto finish;
                                 }
 
-                                if (hashmap_contains(all_services, name))
-                                        service = hashmap_get(all_services, name);
-                                else {
+                                service = hashmap_get(all_services, name);
+                                if (!service){
                                         log_warning("Could not find init script for %s", name);
                                         continue;
                                 }