04_08: Differentiate between DEBUG and ERROR messages

also, don't use stderr directly anymore
diff --git a/openbsc/src/gsm_04_08_utils.c b/openbsc/src/gsm_04_08_utils.c
index 2db46ca..a85f20d 100644
--- a/openbsc/src/gsm_04_08_utils.c
+++ b/openbsc/src/gsm_04_08_utils.c
@@ -340,7 +340,7 @@
 		if ((ra & chr->mask) == chr->val)
 			return ctype_by_chreq[chr->type];
 	}
-	fprintf(stderr, "Unknown CHANNEL REQUEST RQD 0x%02x\n", ra);
+	LOGP(DRR, LOGL_ERROR, "Unknown CHANNEL REQUEST RQD 0x%02x\n", ra);
 	return GSM_LCHAN_SDCCH;
 }
 
@@ -363,7 +363,7 @@
 		if ((ra & chr->mask) == chr->val)
 			return reason_by_chreq[chr->type];
 	}
-	fprintf(stderr, "Unknown CHANNEL REQUEST REASON 0x%02x\n", ra);
+	LOGP(DRR, LOGL_ERROR, "Unknown CHANNEL REQUEST REASON 0x%02x\n", ra);
 	return GSM_CHREQ_REASON_OTHER;
 }
 
@@ -475,7 +475,7 @@
 	if (!msg->lchan->subscr) {
 		msg->lchan->subscr = subscr;
 	} else if (msg->lchan->subscr != subscr) {
-		DEBUGP(DRR, "<- Channel already owned by someone else?\n");
+		LOGP(DRR, LOGL_ERROR, "<- Channel already owned by someone else?\n");
 		subscr_put(subscr);
 		return -EINVAL;
 	} else {
@@ -594,7 +594,8 @@
 	/* in case of multi rate we need to attach a config */
 	if (lchan->tch_mode == GSM48_CMODE_SPEECH_AMR) {
 		if (lchan->mr_conf.ver == 0) {
-			DEBUGP(DRR, "BUG: Using multirate codec without multirate config.\n");
+			LOGP(DRR, LOGL_ERROR, "BUG: Using multirate codec "
+				"without multirate config.\n");
 		} else {
 			u_int8_t *data = msgb_put(msg, 4);
 			data[0] = GSM48_IE_MUL_RATE_CFG;
@@ -634,7 +635,8 @@
 	/* in case of multi rate we need to attach a config */
 	if (lchan->tch_mode == GSM48_CMODE_SPEECH_AMR) {
 		if (lchan->mr_conf.ver == 0) {
-			DEBUGP(DRR, "BUG: Using multirate codec without multirate config.\n");
+			LOGP(DRR, LOGL_ERROR, "BUG: Using multirate codec "
+				"without multirate config.\n");
 		} else {
 			u_int8_t *data = msgb_put(msg, 4);
 			data[0] = GSM48_IE_MUL_RATE_CFG;
@@ -667,7 +669,7 @@
 	DEBUGP(DRR, "CHANNEL MODE MODIFY ACK\n");
 
 	if (mod->mode != msg->lchan->tch_mode) {
-		DEBUGP(DRR, "CHANNEL MODE change failed. Wanted: %d Got: %d\n",
+		LOGP(DRR, LOGL_ERROR, "CHANNEL MODE change failed. Wanted: %d Got: %d\n",
 			msg->lchan->tch_mode, mod->mode);
 		return -1;
 	}