i386: Move all simple string operations out of line

The compiler generally generates reasonable inline code for the simple
cases and for the rest it's better for code size for them to be out of line.
Also there they can be potentially optimized more in the future.

In fact they probably should be in a .S file because they're all pure
assembly, but that's for another day.

Also some code style cleanup on them while I was on it (this seems
to be the last untouched really early Linux code)

This saves ~12k text for a defconfig kernel with gcc 4.1.

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