[PATCH] i386: Fix the EDD code misparsing the command line

The EDD code would scan the command line as a fixed array, without
taking account of either whitespace, null-termination, the old
command-line protocol, late overrides early, or the fact that the
command line may not be reachable from INITSEG.

This should fix those problems, and enable us to use a longer command
line.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andi Kleen <ak@suse.de>