[PATCH] Dynamic kernel command-line: x86_64

1. Rename saved_command_line into boot_command_line.
2. Set command_line as __initdata.

Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>