Staging: bcm: Fix warning: __packed vs. __attribute__((packed)) in Adapter.h

This patch fixes the following warning reported
by checkpatch.pl: "WARNING: __packed is preferred
over __attribute__((packed))".

Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>