voicecall,common: promote call_status_to_string() public

call_status_to_string() is useful for debug output.
Change signature to contain enum call_status
Replace default case to get compiler warning when new enums added

src/common.c

@@ -779,3 +779,24 @@ gint ofono_call_compare(gconstpointer a, gconstpointer b)
 
 	return 0;
 }
+
+const char *ofono_call_status_to_string(enum call_status status)
+{
+	switch (status) {
+	case CALL_STATUS_ACTIVE:
+		return "active";
+	case CALL_STATUS_HELD:
+		return "held";
+	case CALL_STATUS_DIALING:
+		return "dialing";
+	case CALL_STATUS_ALERTING:
+		return "alerting";
+	case CALL_STATUS_INCOMING:
+		return "incoming";
+	case CALL_STATUS_WAITING:
+		return "waiting";
+	case CALL_STATUS_DISCONNECTED:
+		return "disconnected";
+	}
+	return "unknown";
+}

src/common.h

@@ -187,3 +187,4 @@ gboolean is_valid_apn(const char *apn);
 const char *call_status_to_string(enum call_status status);
 
 gint ofono_call_compare(gconstpointer a, gconstpointer b);
+const char *ofono_call_status_to_string(enum call_status status);

src/voicecall.c

@@ -401,7 +401,7 @@ static void append_voicecall_properties(struct voicecall *v,
 	ofono_bool_t mpty;
 	dbus_bool_t emergency_call;
 
-	status = call_status_to_string(call->status);
+	status = ofono_call_status_to_string(call->status);
 
 	ofono_dbus_dict_append(dict, "State", DBUS_TYPE_STRING, &status);
 
@@ -900,7 +900,7 @@ static void voicecall_set_call_status(struct voicecall *call, int status)
 
 	call->call->status = status;
 
-	status_str = call_status_to_string(status);
+	status_str = ofono_call_status_to_string(status);
 	path = voicecall_build_path(call->vc, call->call);
 
 	ofono_dbus_signal_property_changed(conn, path,