patch 8.0.1136: W_WIDTH() is always the same

Problem:    W_WIDTH() is always the same.
Solution:   Expand the macro.
diff --git a/src/if_lua.c b/src/if_lua.c
index ef827ca..bc70293 100644
--- a/src/if_lua.c
+++ b/src/if_lua.c
@@ -1179,7 +1179,7 @@
     else if (strncmp(s, "col", 3) == 0)
 	lua_pushinteger(L, w->w_cursor.col + 1);
     else if (strncmp(s, "width", 5) == 0)
-	lua_pushinteger(L, W_WIDTH(w));
+	lua_pushinteger(L, w->w_width);
     else if (strncmp(s, "height", 6) == 0)
 	lua_pushinteger(L, w->w_height);
     /* methods */