selinux: fix return value on error in policydb_read()

The value of rc is still zero from the last assignment when the error
path is taken. Fix it by setting it to -ENOMEM before the
hashtab_create() call.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: e67b2ec9 ("selinux: store role transitions in a hash table")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/ss/policydb.c

@@ -2540,6 +2540,7 @@ int policydb_read(struct policydb *p, void *fp)
 		goto bad;
 	nel = le32_to_cpu(buf[0]);
 
+	rc = -ENOMEM;
 	p->role_tr = hashtab_create(role_trans_hash, role_trans_cmp, nel);
 	if (!p->role_tr)
 		goto bad;