[S390] atomic: use inline asm

Use inline assemblies for atomic_read/set(). This way there shouldn't
be any questions or subtle volatile semantics left.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 file changed