broadband-bearer: fix crm_range_ready

crm_range_ready() misses a return statement after it invokes
interface_initialization_step(), which will lead to an invalid access of
the already freed InitAsyncContext.

src/mm-broadband-bearer.c

@@ -2210,6 +2210,7 @@ crm_range_ready (MMBaseModem *modem,
                 /* Fine, go on with next step */
                 ctx->step++;
                 interface_initialization_step (ctx);
+                return;
             }
 
             g_assert (error == NULL);