nvme: fix race condition between connected uevent and STARTED_ONCE flag

nvme: fix race condition between connected uevent and STARTED_ONCE flag

When a controller connects, nvme_start_ctrl() emits the
"NVME_EVENT=connected" uevent and sets the NVME_CTRL_STARTED_ONCE flag.
Currently, the uevent is emitted before the flag is set. This creates a
race condition for userspace tools (like udev rules) that might rely on
the "connected" event to configure other attributes.

Swap the order of operations in nvme_start_ctrl() so that the
NVME_CTRL_STARTED_ONCE flag is set before the uevent is sent. This
guarantees that the admin_timeout can already be changed when userspace
is notified.

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>