gsm/gsm0411_smr.c: strip unused variable

Change-Id: I53f69913907588c45a9661c4e86e1bfb57a2418f
diff --git a/src/gsm/gsm0411_smr.c b/src/gsm/gsm0411_smr.c
index 6d7fb8b..eb8aec0 100644
--- a/src/gsm/gsm0411_smr.c
+++ b/src/gsm/gsm0411_smr.c
@@ -287,7 +287,6 @@
 	struct gsm48_hdr *gh = (struct gsm48_hdr*)msg->l3h;
 	struct gsm411_rp_hdr *rp_data = (struct gsm411_rp_hdr*)&gh->data;
 	uint8_t msg_type =  rp_data->msg_type & 0x07;
-	int rc;
 
 	/* check direction */
 	if (inst->network == (msg_type & 1)) {
@@ -329,7 +328,7 @@
 		return -EINVAL;
 	}
 
-	return rc;
+	return 0;
 }
 
 static int gsm411_mnsms_error_ind_tx(struct gsm411_smr_inst *inst,