fix: lib_pin的编译警告修正一下, 缺个末尾的换行

luat/include/luat_pin.h

@@ -6,4 +6,4 @@ int luat_pin_to_gpio(const char* pin_name);
 
 int luat_pin_parse(const char* pin_name, size_t* zone, size_t* index);
 
-#endif
+#endif

luat/modules/luat_lib_pin.c

@@ -78,4 +78,4 @@ static const rotable_Reg_t reg_pin[] =
 LUAMOD_API int luaopen_pin( lua_State *L ) {
     luat_newlib2(L, reg_pin);
     return 1;
-}
+}