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>
diff --git a/drivers/staging/vt6655/device_main.c b/drivers/staging/vt6655/device_main.c
index 83e4162..a3f5cd8 100644
--- a/drivers/staging/vt6655/device_main.c
+++ b/drivers/staging/vt6655/device_main.c
@@ -1669,7 +1669,7 @@
 	.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);