Avoid gcc warning about constant overflow
Avoid gcc warning about constant overflow

In file included from ../../../../ext/pk11_const.c:2:0:
../../../../ext/pk11_const.c: In function ‘Init_pkcs11_const’:
../../../../ext/include/pkcs11t.h:54:36: warning: overflow in implicit constant conversion [-Woverflow]
 define CK_UNAVAILABLE_INFORMATION (~0UL)
                                    ^
../../../../ext/pk11_const_macros.h:9:57: note: in definition of macro ‘PKCS11_DEFINE_CONST’
   rb_define_const(MODULE_FOR_CONSTS, #constant, INT2NUM(constant))
                                                         ^
../../../../ext/pk11_const.c:33:23: note: in expansion of macro ‘CK_UNAVAILABLE_INFORMATION’
   PKCS11_DEFINE_CONST(CK_UNAVAILABLE_INFORMATION);
                       ^
../../../../ext/pk11_const.c: At top level:

larskanis/pkcs11,larskanis/pkcs11