Regression test portability: wc

NetBSD wc displays number with leading spaces, which cause arithmeric
operations on values from wc -l to fail.

Fix the problem by defining a wrappers that removes spaces.

BUG: 1129939
Change-Id: I6fa147cf07772f58d9e19e0efd1dae5dad3a4219
Signed-off-by: Emmanuel Dreyfus <manu@netbsd.org>
Reviewed-on: http://review.gluster.org/9076
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>