scsi: ufs: core: Remove SCSI host only if added

If host tries to remove ufshcd driver from a UFS device it would cause a
kernel panic if ufshcd_async_scan fails during ufshcd_probe_hba before
adding a SCSI host with scsi_add_host and MCQ is enabled since SCSI host
has been defered after MCQ configuration introduced by commit 0cab4023
("scsi: ufs: core: Defer adding host to SCSI if MCQ is supported").

To guarantee that SCSI host is removed only if it has been added, set the
scsi_host_added flag to true after adding a SCSI host and check whether it
is set or not before removing it.

Signed-off-by: Kyoungrul Kim <k831.kim@samsung.com>
Signed-off-by: Minwoo Im <minwoo.im@samsung.com>
Link: https://lore.kernel.org/r/20240627085104epcms2p5897a3870ea5c6416aa44f94df6c543d7@epcms2p5


Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>