LU-6142 ldlm: use list_for_each_entry in ldlm_resource.c

LU-6142 ldlm: use list_for_each_entry in ldlm_resource.c

Having a stand-alone "list_entry()" call is often a sign
that something like "list_for_each_entry()" would
make the code clearer.

Linux-commit: 5eb50608ed0fa076d2783898055fb20934a3828c

Change-Id: I5abd6cc7ec0abd31acc55f5af58f440c4f7609a7
Signed-off-by: Mr. NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49739
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>