Add some useless checks

Signed-off-by: Adrien Gallouët <adrien@gallouet.fr>

src/tun.h

@@ -1,6 +1,6 @@
 #pragma once
 
-int tun_create      (char *, char **);
+int tun_create      (char *, size_t, char *);
 int tun_read        (int, void *, size_t);
 int tun_write       (int, const void *, size_t);
 int tun_set_persist (int, int);