staging: rtl8188eu: use strlcpy instead of strncpy

Use strlcpy instead of strncpy to avoid gcc 8 warning:
warning: '__builtin_strncpy' specified bound 16 equals destination size [-Wstringop-truncation]

The maximum length of the source string including terminating null is 5.
Hence it always fits in the destination buffer of length 16.
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/os_dep/ioctl_linux.c

@@ -1912,7 +1912,7 @@ static int rtw_wx_set_enc_ext(struct net_device *dev,
 		goto exit;
 	}
 
-	strncpy((char *)param->u.crypt.alg, alg_name, IEEE_CRYPT_ALG_NAME_LEN);
+	strlcpy((char *)param->u.crypt.alg, alg_name, IEEE_CRYPT_ALG_NAME_LEN);
 
 	if (pext->ext_flags & IW_ENCODE_EXT_SET_TX_KEY)
 		param->u.crypt.set_tx = 1;