Fix fallback processing for ktc_GetTokenEx()

Fix fallback processing for ktc_GetTokenEx()

The fallback processing after ktc_GetToken() generates
a token set or fails.  Immediately return 'code' to the
caller after freeing ktcToken.

Change-Id: If82c5c94b75152eaa4d077b428238e8f77478d05
Reviewed-on: http://gerrit.openafs.org/3544
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Jeffrey Altman <jaltman@openafs.org>