LU-4629 obdclass: compile issues with variable not being initialized

LU-4629 obdclass: compile issues with variable not being initialized

One of the versions of gcc I have refuses to build obd_mount.c due to
index not be initialized in function lmd_make_exclusion before it is
used.

Change-Id: Ib549e595492e647364441c5d96df86ec513ad6c6
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Reviewed-on: http://review.whamcloud.com/10705
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>