scsi: sg: Fix get_user() in call sg_scsi_ioctl()

get_user() expects the pointer to be pointer-to-simple-variable type, but
sic->data is array of 'unsigned char'. It violates get_user() contracts.

Explicitly take pointer to the first element of the array. It matches
current behaviour.

This is preparation for fixing sparse warnings caused by Linear Address
Masking patchset.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/20221117232304.1544-1-kirill.shutemov@linux.intel.com
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_ioctl.c

@@ -519,7 +519,7 @@ static int sg_scsi_ioctl(struct request_queue *q, fmode_t mode,
 		return -EFAULT;
 	if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
 		return -EINVAL;
-	if (get_user(opcode, sic->data))
+	if (get_user(opcode, &sic->data[0]))
 		return -EFAULT;
 
 	bytes = max(in_len, out_len);