i40e: Fix NULL pointer dereference in i40e_dbg_dump_desc

stable inclusion
from stable-v5.10.85
commit e5b7fb2198abc50058f1a29c395b004f76ab1c83
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9S22G
CVE: CVE-2021-47501

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e5b7fb2198abc50058f1a29c395b004f76ab1c83



--------------------------------

commit 23ec111b upstream.

When trying to dump VFs VSI RX/TX descriptors
using debugfs there was a crash
due to NULL pointer dereference in i40e_dbg_dump_desc.
Added a check to i40e_dbg_dump_desc that checks if
VSI type is correct for dumping RX/TX descriptors.

Fixes: 02e9c290 ("i40e: debugfs interface")
Signed-off-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>
Signed-off-by: Norbert Zulinski <norbertx.zulinski@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Conflicts:
	drivers/net/ethernet/intel/i40e/i40e_debugfs.c
[ Conflicts caused by not merging 44ea803e ("i40e: introduce new dump
desc XDP command"). ]
Signed-off-by: Li Huafei <lihuafei1@huawei.com>