s3:winbind: Refactor winbindd_pam_auth_crap_{send,recv}

s3:winbind: Refactor winbindd_pam_auth_crap_{send,recv}

The winbindd_dual_pam_auth_crap() will be converted to a local RPC call
handler and the winbindd_response won't be filled by the child process
but in the parent's winbindd_pam_auth_crap_recv() function.

Move all code filling the winbindd_response struct to a common place,
winbindd_pam_auth_crap_recv().

Signed-off-by: Samuel Cabrero <scabrero@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>