selinux: avtab_init() and cond_policydb_init() return void

The avtab_init() and cond_policydb_init() functions always return
zero so mark them as returning void and update the callers not to
check for a return value.

Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/ss/avtab.h

@@ -87,7 +87,7 @@ struct avtab {
 	u32 mask;       /* mask to compute hash func */
 };
 
-int avtab_init(struct avtab *);
+void avtab_init(struct avtab *h);
 int avtab_alloc(struct avtab *, u32);
 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
 void avtab_destroy(struct avtab *h);