BugLink: https://bugs.launchpad.net/bugs/1860681

commit 906ca635 upstream.

This error path is missing an unlock.

Fixes: 26780d9e ("[SCSI] esas2r: ATTO Technology ExpressSAS 6G SAS/SATA RAID Adapter Driver")
Link: https://lore.kernel.org/r/20191022102324.GA27540@mwandaSigned-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>