getopt: tidy up _getopt_initialize a bit

getopt: tidy up _getopt_initialize a bit

_getopt_data.__posixly_correct is completely redundant to
_getopt_data.__ordering, and some work that logically belongs in
_getopt_initialize was being done by _getopt_internal_r, making the
code harder to understand.

As a side effect, getenv will no longer be called if the first
character of the options string is '+' or '-', which is probably a
Good Thing.  (Perhaps we should have a flag character that
specifically asks for the permutation behavior?)

	* posix/getopt_int.h (_getopt_data): Remove __posixly_correct field.
	* posix/getopt.c (_getopt_internal_r): Move some initialization code...
	(_getopt_initialize): ...here. Don't set d->__posixly_correct.