staging: vt6655: Declare vnt_init() static

Fix sparse warning:
  drivers/staging/vt6655/device_main.c:1672:5: warning: symbol 'vnt_init' was not declared. Should it be static?
Signed-off-by: Sören Brinkmann <soeren.brinkmann@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6655/device_main.c

@@ -1669,7 +1669,7 @@ static const struct ieee80211_ops vnt_mac_ops = {
 	.reset_tsf		= vnt_reset_tsf,
 };
 
-int vnt_init(struct vnt_private *priv)
+static int vnt_init(struct vnt_private *priv)
 {
 	SET_IEEE80211_PERM_ADDR(priv->hw, priv->abyCurrentNetAddr);