Remove 'NO_HW' devices from `ioscan`.

When you pull a disk out of an HPUX system, `ioscan` will still show the device:

# ioscan -fnCdisk
Class     I  H/W Path     Driver S/W State   H/W Type     Description
=====================================================================
disk      0  0/1/1/0.0.0  sdisk CLAIMED     DEVICE       HP 73.4GST373454LC
                      /dev/dsk/c2t0d0   /dev/rdsk/c2t0d0
disk      1  0/1/1/0.1.0  sdisk NO_HW       DEVICE       HP 73.4GST373454LC
                      /dev/dsk/c2t1d0   /dev/rdsk/c2t1d0
disk      2  0/1/1/1.2.0  sdisk NO_HW       DEVICE       HP 73.4GST373454LC
                      /dev/dsk/c3t2d0   /dev/rdsk/c3t2d0

Here's how to remove all 'NO_HW' devices from the `ioscan` output:

ioscan -fCdisk|grep NO_HW|awk '{print $3}'|xargs -i -t rmsf -H {}