vmlinux.lds: move __attribute__((__cold__)) functions back into final .text section

Due to the addition of __attribute__((__cold__)) to a few symbols
without adjusting the linker scripts, those symbols currently may end
up outside the [_stext,_etext) range, as they get placed in
.text.unlikely by (at least) gcc 4.3.0. This may confuse code not only
outside of the kernel, symbol_put_addr()'s BUG() could also trigger.
Hence we need to add .text.unlikely (and for future uses of
__attribute__((__hot__)) also .text.hot) to the TEXT_TEXT() macro.

Issue observed by Lukas Lipavsky.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Tested-by: Lukas Lipavsky <llipavsky@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>