rx: Set but not used variables

rx: Set but not used variables

Remove some unused variables in the rx code.
These generate warnings with gcc 4.6.

Change-Id: I1e19c82cd05bcd47a65d77079019f1f0b6704826
Reviewed-on: http://gerrit.openafs.org/2732
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit a8cf472fd1723fa0e5f4edc34e470443c941f017)
Reviewed-on: http://gerrit.openafs.org/2794