selinux: fix error codes in symtab_init()

hashtab_create() only returns NULL on allocation failures to -ENOMEM is
appropriate here.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

security/selinux/ss/symtab.c

@@ -36,7 +36,7 @@ int symtab_init(struct symtab *s, unsigned int size)
 {
 	s->table = hashtab_create(symhash, symcmp, size);
 	if (!s->table)
-		return -1;
+		return -ENOMEM;
 	s->nprim = 0;
 	return 0;
 }