I'm unsure where all these %%s before register names comes from,
but they confuse clang, like this:

> criu/arch/arm/parasite-head.S:6:6: error: unexpected token in operand
>  sub %r2, %pc, #8 @ get the address of this instruction
>     ^

This patch looks scary, but all it does is removing %s before
register names, fixing a few "many spaces instead of a tab" issues
along the way.

travis-ci: success for Fixes to compile on arm with clang
Cc: Christopher Covington <cov@codeaurora.org>
Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>