nvme-tcp: store negative errno in queue->tls_err

nvme-tcp: store negative errno in queue->tls_err

nvme_tcp_tls_done() assigns queue->tls_err in three branches.  The
ENOKEY lookup failure and the EOPNOTSUPP initializer both store
negative errnos.  The third branch, reached when the handshake
layer reports a non-zero status, stores -status.

The handshake layer delivers status to the consumer callback as a
negative errno; the other in-tree consumers --
xs_tls_handshake_done() and the nvmet target callback -- treat
their status argument that way.  The extra negation in
nvme_tcp_tls_done() flips the sign, leaving tls_err as a positive
value (for instance, +EIO), which nvme_tcp_start_tls() then
returns to its caller.

Drop the extra negation so queue->tls_err uniformly carries a
negative errno on failure.

Fixes: be8e82caa685 ("nvme-tcp: enable TLS handshake upcall")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Link: https://patch.msgid.link/20260525-handshake-file-pin-v3-2-66c616906ead@oracle.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>