BACKPORT: FROMGIT: scsi: ufs: Protect PM ops and err_handler from user access through sysfs

User layer may access sysfs nodes when system PM ops or error handling is
running. This can cause various problems. Rename eh_sem to host_sem and use
it to protect PM ops and error handling from user layer intervention.

Link: https://lore.kernel.org/r/1610594010-7254-3-git-send-email-cang@codeaurora.org


Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Acked-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Bug: 189457922
(cherry picked from commit 9cd20d3f
git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git

 5.14/scsi-queue)
[Can Guo: Resolved minor conflict in ufshcd.c]
Change-Id: I705627ce4c78849f8c21f96cb98e8f66a562c183
Signed-off-by: Can Guo <cang@codeaurora.org>