viced.c: Don't store results of reads unecessarily

viced.c: Don't store results of reads unecessarily

When we don't need to store the amount of data read from a file,
don't complicate the if() statement by adding a pointless assignment.

Caught by clang-analyzer

Change-Id: I326d894c9b5f7a89f31534c7864e05ea059a03aa
Reviewed-on: http://gerrit.openafs.org/5079
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>