vti: use alternative way to check if kernel support is enabled

When necessary support is built in kernel, vti protocol support is
not enabled in netifd.

Signed-off-by: Alin Nastac <[email protected]>

package/network/config/vti/Makefile

@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=vti
-PKG_RELEASE:=3
+PKG_RELEASE:=4
 PKG_LICENSE:=GPL-2.0
 
 include $(INCLUDE_DIR)/package.mk

package/network/config/vti/files/vti.sh

@@ -149,6 +149,6 @@ proto_vti6_init_config() {
 }
 
 [ -n "$INCLUDE_ONLY" ] || {
-	[ -f /lib/modules/$(uname -r)/ip_vti.ko ] && add_protocol vti
-	[ -f /lib/modules/$(uname -r)/ip6_vti.ko ] && add_protocol vti6
+	[ -d /sys/module/ip_vti ] && add_protocol vti
+	[ -d /sys/module/ip6_vti ] && add_protocol vti6
 }