vol: initialize FdHandle_t stack objects

vol: initialize FdHandle_t stack objects

In namei_create() a temporary FdHandle_t is allocated on
the stack but was never initialized.  Depending on what
prior data was on the stack the FdHandle_t could result
in subsequent operations failing in unpredictable ways.

Change-Id: I6246930adc87cf84ad9c0913cda2d00e6f851bc1
Reviewed-on: http://gerrit.openafs.org/3667
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>