a_iface: Consistent and understandable function names

Change-Id: I36894e68e4b1f25f266e941c39a44e0171d24689
diff --git a/src/libmsc/a_iface.c b/src/libmsc/a_iface.c
index ed6dcdb..86c2e04 100644
--- a/src/libmsc/a_iface.c
+++ b/src/libmsc/a_iface.c
@@ -234,7 +234,7 @@
 }
 
 /* Convert speech version field */
-static uint8_t convert_l3_sv_to_A_sv(int speech_ver)
+static uint8_t convert_speech_version_l3_to_A(int speech_ver)
 {
 	/* The speech versions that are transmitted in the Bearer capability
 	 * information element, that is transmitted on the Layer 3 (CC)
@@ -270,7 +270,7 @@
 }
 
 /* Convert speech preference field */
-static uint8_t convert_l3_prev_to_A_pref(int radio)
+static uint8_t convert_speech_pref_l3_to_A(int radio)
 {
 	/* The Radio channel requirement field that is transmitted in the
 	 * Bearer capability information element, that is transmitted on the
@@ -309,7 +309,7 @@
 	for (i = 0; i < ARRAY_SIZE(bc->speech_ver); i++) {
 		if (bc->speech_ver[i] == -1)
 			break;
-		sv = convert_l3_sv_to_A_sv(bc->speech_ver[i]);
+		sv = convert_speech_version_l3_to_A(bc->speech_ver[i]);
 		if (sv != 0xFF) {
 			/* Detect if something else than
 			 * GSM HR V1 is supported */
@@ -331,7 +331,7 @@
 		 * preference and assume a preference for full rate. */
 		ct->ch_rate_type = GSM0808_SPEECH_FULL_BM;
 	else
-		ct->ch_rate_type = convert_l3_prev_to_A_pref(bc->radio);
+		ct->ch_rate_type = convert_speech_pref_l3_to_A(bc->radio);
 
 	if (count)
 		return 0;