The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from initrd_user.c file under os-Linux dir and join
initrd_user.c and initrd_kern.c files in new file initrd.c
Signed-off-by: NGennady Sharapov <Gennady.V.Sharapov@intel.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>