LU-7090 deb: fix wrong IB path for configure

LU-7090 deb: fix wrong IB path for configure

There are two problems:

Firstly, we need check whether O2IBPATH is valid before using
if not, asssign '--with-o2ib=no'instead.

Secondly, macro O2IBPATHS might be "$LINUX $LINUX/drivers/infiniband".
--with-o2ib only expect one string assignment here

Signed-off-by: Wang Shilong <wshilong@ddn.com>
Change-Id: I86172056c57ec8e649c2e56455369e66bbbe3513
Reviewed-on: http://review.whamcloud.com/16183
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>