MINOR: hlua: some luaL_checktype() calls were not guarded with MAY_LJMP

MINOR: hlua: some luaL_checktype() calls were not guarded with MAY_LJMP

In hlua code, we mark every function that may longjump using
MAY_LJMP macro so it's easier to identify them by reading the code.

However, some luaL_checktypes() were performed without the MAY_LJMP.

According to lua doc:
	Functions called luaL_check* always raise an error if
	the check is not satisfied.

-> Adding the missing MAY_LJMP for those luaLchecktypes() calls.

No backport needed.