drivers: s390: move static and inline before return type

Make the code like the rest of the kernel.

Link: http://lkml.kernel.org/r/3f980cd89084ae09716353aba3171e4b3815e690.1499284835.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Cc: Ursula Braun <ubraun@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>