Fix endianess problem in cramfs code (cramfs is always host-endian in Linux)

Originally pointed out by Laurent Pinchart <laurent.pinchart@tbox.biz>,
see http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/22846

Signed-off-by: Bernhard Nemec <bnemec <at> ganssloser.com>