Fix nfc_target_init() timeout return

This patch prevent from returning a successfull error code while timeout occurred.

Thanks to blck on forum:
http://www.libnfc.org/community/post/4913/#p4913

libnfc/chips/pn53x.c

@@ -1911,7 +1911,7 @@ pn53x_target_init(struct nfc_device *pnd, nfc_target *pnt, uint8_t *pbtRx, const
 
     if ((res = pn53x_TgInitAsTarget(pnd, ptm, pbtMifareParams, pbtTkt, szTkt, pbtFeliCaParams, pbtNFCID3t, pbtGBt, szGBt, pbtRx, szRxLen, &btActivatedMode, timeout)) < 0) {
       if (res == NFC_ETIMEOUT) {
-        return pn53x_idle(pnd);
+        pn53x_idle(pnd);
       }
       return res;
     }