rfkill: add type string helper

We will need access to the rfkill switch type in string format for more
than just sysfs.  Therefore, move it to a generic helper.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/rfkill/rfkill.c

@@ -224,34 +224,31 @@ static ssize_t rfkill_name_show(struct device *dev,
 	return sprintf(buf, "%s\n", rfkill->name);
 }
 
-static ssize_t rfkill_type_show(struct device *dev,
-				struct device_attribute *attr,
-				char *buf)
+static const char *rfkill_get_type_str(enum rfkill_type type)
 {
-	struct rfkill *rfkill = to_rfkill(dev);
-	const char *type;
-
-	switch (rfkill->type) {
+	switch (type) {
 	case RFKILL_TYPE_WLAN:
-		type = "wlan";
-		break;
+		return "wlan";
 	case RFKILL_TYPE_BLUETOOTH:
-		type = "bluetooth";
-		break;
+		return "bluetooth";
 	case RFKILL_TYPE_UWB:
-		type = "ultrawideband";
-		break;
+		return "ultrawideband";
 	case RFKILL_TYPE_WIMAX:
-		type = "wimax";
-		break;
+		return "wimax";
 	case RFKILL_TYPE_WWAN:
-		type = "wwan";
-		break;
+		return "wwan";
 	default:
 		BUG();
 	}
+}
+
+static ssize_t rfkill_type_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "%s\n", type);
+	return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
 }
 
 static ssize_t rfkill_state_show(struct device *dev,