bdev/nvme: Remove get_admin_qp_failure_reason from qpair_is_connected

For NVMe multipath, if active/passive is used, bdev_nvme_find_io_path()
is rarely called, but if active/active is used, bdev_nvme_find_io_path()
is very frequently called.

If active/passive used, the primary path will be used for a long time.
It may be reasonable to do all possible checks in
nvme_qpair_is_connected().

However, spdk_nvme_ctrlr_get_admin_qp_failure_reason() caused visible
overhead for large scale configuration and small rr_min_io (e.g., 4).

First of all, admin qpair and I/O qpair are independent with each other
and this check was not necessary.

Let's remove spdk_nvme_ctrlr_get_admin_qp_failure_reason() call from
nvme_qpair_is_connected().

Signed-off-by: Shuhei Matsumoto <smatsumoto@nvidia.com>
Change-Id: I19591f3befc319c3d1813ba75b2a999f8a24cd62
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/20704


Reviewed-by: Jim Harris <jim.harris@samsung.com>
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@nvidia.com>