LU-12756 lnet: Remove unused vars in lnet_find_route_locked

LU-12756 lnet: Remove unused vars in lnet_find_route_locked

The lp and lp_best variables are not needed in
lnet_find_route_locked().

Test-Parameters: trivial
Signed-off-by: Chris Horn <hornc@cray.com>
Change-Id: I61a7097ab66703a1af1346c7301b9efc7e4392c9
Reviewed-on: https://review.whamcloud.com/36620
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alexandr Boyko <c17825@cray.com>
Reviewed-by: Alexey Lyashkov <c17817@cray.com>
Reviewed-by: Amir Shehata <ashehata@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>