Autoconf: Tidy up resolver retrans retry test

Autoconf: Tidy up resolver retrans retry test

There's no need for the retrans retry test to be a TRY_RUN test,
TRY_COMPILE will pick up the existence of the '_res' structure and
its elements.

Also, clean up the use of the cache variable to set the result. In
the old implementation a true test result would print '1', not 'yes',
a false result would result in bad output in the config.log, and a
cross compiling output would give
  #define HAVE_RES_RETRANSRETRY no
which will give unexpected results with #ifdef tests.

Change-Id: If78c1b01ee89242c67f87238ca502ce43718c6a2
Reviewed-on: http://gerrit.openafs.org/2014
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>