LU-18388 llite: handle -EOPNOTSUPP in get_inode_acl

LU-18388 llite: handle -EOPNOTSUPP in get_inode_acl

When ll_xattr_list returns -EOPNOTSUPP [-95] NULL should be
returned to avoid sanity failing to run as non-root users with:

 operation mds_getxattr to node 192.168.122.50@tcp failed:  rc = -95

Test-Parameters: testlist=sanity env=ONLY=103a,ONLY_REPEAT=10  mdscount=2 mdtcount=4 osscount=1 ostcount=8 clientcount=2  clientdistro=sles15sp6 serverdistro=el8.8
Test-Parameters: testlist=sanity env=ONLY=103a,ONLY_REPEAT=10  mdscount=2 mdtcount=4 osscount=1 ostcount=8 clientcount=2  clientdistro=ubuntu2404 serverdistro=el8.8
Test-Parameters: testlist=sanity env=ONLY=103a,ONLY_REPEAT=10  mdscount=2 mdtcount=4 osscount=1 ostcount=8 clientcount=2  clientdistro=el9.3 serverdistro=el8.8
Test-Parameters: testlist=sanityn env=ONLY=25a,ONLY_REPEAT=10  mdscount=2 mdtcount=4 osscount=1 ostcount=8 clientcount=2  clientdistro=ubuntu2404 serverdistro=el8.8
Test-Parameters: testlist=sanity-sec env=ONLY=23b,ONLY_REPEAT=50  mdscount=2 mdtcount=4 osscount=1 ostcount=8 clientcount=2  clientdistro=ubuntu2404 serverdistro=el8.8
Fixes: 13fd5ebef3 ("LU-18101 sec: fix ACL handling on recent kernels again")
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I208e7e6095c19728643a6d208becd448ed2e2539
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56756
Tested-by: Maloo <maloo@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>