vol: Remove unneeded braces

Doing if ((a==b)) is unecessary. It's also potentially dangerous, as
that's the syntax required to do assignment within an if statement.
clang now issues warnings (errors in -Werror mode) when it encounters
these.

Remove pointless braces from vol to make clang happy.

Reviewed-on: http://gerrit.openafs.org/7082
Reviewed-by: Derrick Brashear <shadow@dementix.org>
Tested-by: Derrick Brashear <shadow@dementix.org>
(cherry picked from commit 58be19d792e6b8e93fbd49bc4ef04bbb8f4560ef)

Change-Id: Ie2fd97927eace8a9317598c1b44d2c2610cdc31a
Reviewed-on: http://gerrit.openafs.org/10739
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>