screen: makes luaA_pushscreen static

Signed-off-by: Julien Danjou <julien@danjou.info>

screen.c

@@ -343,7 +343,7 @@ screen_client_moveto(client_t *c, screen_t *new_screen, bool doresize)
  * \param s The screen to push.
  * \return The number of elements pushed on stack.
  */
-int
+static int
 luaA_pushscreen(lua_State *L, screen_t *s)
 {
     lua_pushlightuserdata(L, s);

screen.h

@@ -59,7 +59,6 @@ area_t screen_area_get(screen_t *, bool);
 area_t display_area_get(int);
 int screen_virttophys(int);
 void screen_client_moveto(client_t *, screen_t *, bool);
-int luaA_pushscreen(lua_State *, screen_t *);
 
 #endif
 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80