scsi: qla2xxx: Fix loss of NVMe namespaces after driver reload test

Driver registration of localport can race when it happens at the remote
port discovery time. Fix this by calling the registration under a mutex.

Link: https://lore.kernel.org/r/20220310092604.22950-4-njavali@marvell.com
Fixes: e84067d7

 ("scsi: qla2xxx: Add FC-NVMe F/W initialization and transport registration")
Cc: stable@vger.kernel.org
Reported-by: Marco Patalano <mpatalan@redhat.com>
Tested-by: Marco Patalano <mpatalan@redhat.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>