s390/sclp_sdias: remove unused sclp_sdias_exit

sclp_sdias cannot be built as a module, CRASH_DUMP option is a bool not a
tristate. zcore_exit() has already been removed with commit cbe62fac
("s390: char: make zcore explicitly non-modular"). Remove orphaned
sclp_sdias_exit for consistency as well.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

drivers/s390/char/sclp.h

@@ -305,9 +305,7 @@ int sclp_deactivate(void);
 int sclp_reactivate(void);
 int sclp_sync_request(sclp_cmdw_t command, void *sccb);
 int sclp_sync_request_timeout(sclp_cmdw_t command, void *sccb, int timeout);
-
 int sclp_sdias_init(void);
-void sclp_sdias_exit(void);
 
 enum {
 	sclp_init_state_uninitialized,

drivers/s390/char/sclp_sdias.c

@@ -275,9 +275,3 @@ int __init sclp_sdias_init(void)
 	TRACE("init done\n");
 	return 0;
 }
-
-void __exit sclp_sdias_exit(void)
-{
-	debug_unregister(sdias_dbf);
-	sclp_unregister(&sclp_sdias_register);
-}