LU-16037 build: remove quotes from %{mkconf_options}

LU-16037 build: remove quotes from %{mkconf_options}

This patch fixes lustre-dkms.spec.in to remove quotes
from %{mkconf_options} passed to dkms.mkconf, so as to
resolve the following build issue:

dkms.conf: Error! Directive 'DEST_MODULE_LOCATION'
does not begin with '/kernel', '/updates', or '/extra'
in record #0.

Lustre-change: https://review.whamcloud.com/48044
Lustre-commit: 33efefc496159f7d0caed0fa85d8f92603060ae2

Test-Parameters: trivial

Change-Id: I0b365d7a96cb632680bc2321e87b28a3bf076e47
Signed-off-by: Jian Yu <yujian@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/48118
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Colin Faber <cfaber@ddn.com>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Nathaniel Clark <nclark@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>