Typo in VMS-specific code prevents #definition of BISON_HAIRY

[Kevin Goodsell]

I don't know where to look for lists of bugs that have been found, so
please ignore me if this is already known (which seems likely, since I
believe it should prevent compilation on VMS).

I noticed the following code from system.h:

#if defined (VMS) & !defined (__VMS_POSIX)
# ifndef BISON_SIMPLE
#  define BISON_SIMPLE "GNU_BISON:[000000]BISON.SIMPLE"
# endif
# ifndef BISON_HAIRY
#  define BISON_HARIRY "GNU_BISON:[000000]BISON.HAIRY"
# endif
#endif

I haven't tried building on VMS, but it looks obvious that the wrong
symbol is being #defined. BISON_HARIRY should be BISON_HAIRY.

-Kevin