[SCSI] gdth: fix oops in gdth_copy_cmd()

Recent alterations to the gdth_fill_raw_cmd() path no longer set the
sg_ranz field for zero transfer commands. However, this field is used
lower down in the function to initialise ha->cmd_len to the size of
the firmware packet.  If this uninitialised field contains a bogus
value, ha->cmd_len can become much larger than the actual firmware
packet and end up oopsing in gdth_copy_cmd() as it tries to copy this
huge packet to the device (usually because it runs into an unallocated
page).

The fix is to initialise the sg_ranz field to zero at the start of
gdth_fill_raw_cmd().

Signed-off-by: Joerg Dorchain <joerg@dorchain.net>
Acked-by: "Leubner, Achim" <Achim_Leubner@adaptec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/gdth.c

@@ -3091,6 +3091,7 @@ static int gdth_fill_raw_cmd(int hanum,Scsi_Cmnd *scp,unchar b)
             cmdp->u.raw64.direction  = 
                 gdth_direction_tab[scp->cmnd[0]]==DOU ? GDTH_DATA_OUT:GDTH_DATA_IN;
             memcpy(cmdp->u.raw64.cmd,scp->cmnd,16);
+            cmdp->u.raw64.sg_ranz    = 0;
         } else {
             cmdp->u.raw.reserved   = 0;
             cmdp->u.raw.mdisc_time = 0;
@@ -3107,6 +3108,7 @@ static int gdth_fill_raw_cmd(int hanum,Scsi_Cmnd *scp,unchar b)
             cmdp->u.raw.direction  = 
                 gdth_direction_tab[scp->cmnd[0]]==DOU ? GDTH_DATA_OUT:GDTH_DATA_IN;
             memcpy(cmdp->u.raw.cmd,scp->cmnd,12);
+            cmdp->u.raw.sg_ranz    = 0;
         }
 
         if (scp->use_sg) {