staging: r8188eu: Remove ODM_CompareMemory

This routine is a wrapper for _rtw_memcmp(), which is a wrapper for memcmp.
In a later change, _rtw_memcmp will be removed.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>