linux_sg.c modification for SCSI Test Unit Ready command

[Tracy Di Marco White <netbsd-t%menelos.com@localhost>]

I've needed to add emulation for the SCSI Test Unit Ready command
to my backup server, so I could run Sony's tape diagnostics.
It's fairly simple, but is it the correct flag to use for that?
The patch below is what I'm using on my 4.0 backup server.

-Tracy

Index: linux_sg.c
===================================================================
RCS file: /cvsroot/src/sys/compat/linux/common/linux_sg.c,v
retrieving revision 1.8
diff -r1.8 linux_sg.c
109a110
>                       /* e.g. a SCSI WRITE command */
112a114
>                        /* e.g. a SCSI READ command */
114a117,120
>               case SG_DXFER_NONE:
>                       /* e.g. a SCSI Test Unit Ready command */
>                       req.flags = SCCMD_ESCAPE;
>                       break;