ieee802154: cc2520: use __func__ macro for debug messages

Instead of having the function name hard-coded (it might change and we
forgot to update them in the debug output) we can use __func__ instead
and also shorter the line so we do not need to break it.
Found by checkpatch.

Signed-off-by: Stefan Schmidt <[e-mail]>
Acked-by: Varka Bhadram <[e-mail]>
Signed-off-by: Stefan Schmidt <[e-mail]>

drivers/net/ieee802154/cc2520.c

···
 	if (changed & IEEE802154_AFILT_PANID_CHANGED) {
 		u16 panid = le16_to_cpu(filt->pan_id);
 
-		dev_vdbg(&priv->spi->dev,
-			 "cc2520_filter called for pan id\n");
+		dev_vdbg(&priv->spi->dev, "%s called for pan id\n", __func__);
 		ret = cc2520_write_ram(priv, CC2520RAM_PANID,
 				       sizeof(panid), (u8 *)&panid);
 	}
 
 	if (changed & IEEE802154_AFILT_IEEEADDR_CHANGED) {
 		dev_vdbg(&priv->spi->dev,
-			 "cc2520_filter called for IEEE addr\n");
+			 "%s called for IEEE addr\n", __func__);
 		ret = cc2520_write_ram(priv, CC2520RAM_IEEEADDR,
 				       sizeof(filt->ieee_addr),
 				       (u8 *)&filt->ieee_addr);
···
 	if (changed & IEEE802154_AFILT_SADDR_CHANGED) {
 		u16 addr = le16_to_cpu(filt->short_addr);
 
-		dev_vdbg(&priv->spi->dev,
-			 "cc2520_filter called for saddr\n");
+		dev_vdbg(&priv->spi->dev, "%s called for saddr\n", __func__);
 		ret = cc2520_write_ram(priv, CC2520RAM_SHORTADDR,
 				       sizeof(addr), (u8 *)&addr);
 	}
···
 		u8 frmfilt0;
 
 		dev_vdbg(&priv->spi->dev,
-			 "cc2520_filter called for panc change\n");
+			 "%s called for panc change\n", __func__);
 
 		cc2520_read_register(priv, CC2520_FRMFILT0, &frmfilt0);