Windows: Remove fallback from GetCaps to GetTime

Windows: Remove fallback from GetCaps to GetTime

If the file server responds to RXAFS_GetCapabilities with
RXGEN_OPCODE the server is up and there is no need to fallback to
RXAFS_GetTime.  Remove the code that performs the extra work.

Change-Id: Ieb0d1cce6f356a8988f2464227dec9b6cd9e6fcf
Reviewed-on: http://gerrit.openafs.org/3419
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>