[S390] Get rid of init_module/delete_module compat functions.

These functions aren't needed. Might be a leftover of the pre
cond_syscall time.

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