tuntap: fix for "tuntap: XDP transmission"

Fixes: fc72d1d5 ("tuntap: XDP transmission")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_tun.h

@@ -42,11 +42,11 @@ static inline bool tun_is_xdp_buff(void *ptr)
 {
 	return false;
 }
-void *tun_xdp_to_ptr(void *ptr)
+static inline void *tun_xdp_to_ptr(void *ptr)
 {
 	return NULL;
 }
-void *tun_ptr_to_xdp(void *ptr)
+static inline void *tun_ptr_to_xdp(void *ptr)
 {
 	return NULL;
 }