[Bug libgomp/91694] configure.ac does not correctly check for gethostname

[rishi@extreme-scale.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91694

--- Comment #2 from Rishi Khan <rishi@extreme-scale.com> ---
Created attachment 46857
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46857&action=edit
patch for libgomp

Attached is a patch that works for me.