libxbps: simplify pkgdb_get_pkgd and find_pkg_dict_installed internals.

There's no need to prop_dictionary_copy the returned dictionary to
later have to free it again, just return directly the dictionary and
avoid the free(3)s.

lib/package_register.c

@@ -137,9 +137,6 @@ xbps_register_pkg(struct xbps_handle *xhp, prop_dictionary_t pkgrd, bool flush)
 		goto out;
 	}
 out:
-	if (pkgd != NULL)
-		prop_object_release(pkgd);
-
 	if (rv != 0) {
 		xbps_set_cb_state(xhp, XBPS_STATE_REGISTER_FAIL,
 		    rv, pkgname, version,