[SCSI] sr: fix error code check in sr_block_ioctl()

sr_block_ioctl() should proceed to SCSI ioctls if cdrom_ioctl()
returns -ENOSYS.  However it tested for ENOSYS instead of -ENOSYS
rendering all SCSI ioctls other than GET_IDLUN and GET_BUS_NUMBER
inaccessible.  Fix it.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/sr.c

@@ -468,7 +468,7 @@ static int sr_block_ioctl(struct inode *inode, struct file *file, unsigned cmd,
 	}
 
 	ret = cdrom_ioctl(file, &cd->cdi, inode, cmd, arg);
-	if (ret != ENOSYS)
+	if (ret != -ENOSYS)
 		return ret;
 
 	/*