scsi: libfc: fixup 'sleeping function called from invalid context'

[ Upstream commit fa519f701d27198a2858bb108fc18ea9d8c106a7 ]

fc_rport_login() will be calling mutex_lock() while running inside an
RCU-protected section, triggering the warning 'sleeping function called
from invalid context'.  To fix this we can drop the rcu functions here
altogether as the disc mutex protecting the list itself is already held,
preventing any list manipulation.

Fixes: a407c593 ("scsi: libfc: Fixup disc_mutex handling")
Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>