Remove dead code

RX_ENABLE_TSFPQ is never defined for KERNEL builds.

In any case, there's a syntax error in the removed code, with a
missing '&' before rx_stats.receivePktAllocFailures.

Change-Id: I3aaf3d80f7dfee6836016b65b057e1312d716368
Reviewed-on: http://gerrit.openafs.org/11543
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: D Brashear <shadow@your-file-system.com>