Staging: w35und: remove memcpy/memcmp wrappers

The OS_MEMORY_CLEAR macro is not used so remove it. Also convert the one
call-site that uses OS_MEMORY_COMPARE to use memcmp() directly and remove the
wrapper macro.

Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>