[PATCH] x86_64: Recover 1MB of kernel memory

Noticed by Jan Beulich.

When the kernel was moved from 1MB to 2MB in 2.6.17 the kernel reservation
code wasn't adjusted and it still reserved starting with 1MB. This means 1MB always
were lost.

This patch fixes this by reserving only starting with _text.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>