scsi: sg: Avoid sg device teardown race

scsi: sg: Avoid sg device teardown race

sg_remove_sfp_usercontext() must not use sg_device_destroy() after calling
scsi_device_put().

sg_device_destroy() is accessing the parent scsi_device request_queue which
will already be set to NULL when the preceding call to scsi_device_put()
removed the last reference to the parent scsi_device.

The resulting NULL pointer exception will then crash the kernel.

Link: https://lore.kernel.org/r/20240305150509.23896-1-Alexander@wetzel-home.de
Fixes: db59133e9279 ("scsi: sg: fix blktrace debugfs entries leakage")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Wetzel <Alexander@wetzel-home.de>
Link: https://lore.kernel.org/r/20240320213032.18221-1-Alexander@wetzel-home.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>