[PATCH] Remove dtb file created by wrapper script

When the wrapper script is passed a dts file, it runs 'dtc' to create
a dtb file.  This patch deletes that dtb file once its no longer needed.

Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>