Fix type definitions, module init return values, and unicode/bytes conversions
diff --git a/OpenSSL/crypto/pkcs7.c b/OpenSSL/crypto/pkcs7.c
index 8bfddb3..fff95e2 100644
--- a/OpenSSL/crypto/pkcs7.c
+++ b/OpenSSL/crypto/pkcs7.c
@@ -161,7 +161,7 @@
 }
 
 PyTypeObject crypto_PKCS7_Type = {
-    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    PyOpenSSL_HEAD_INIT(&PyType_Type, 0)
     "PKCS7",
     sizeof(crypto_PKCS7Obj),
     0,