revert HMAC changes

Author: picnixz

Modules/_hashopenssl.c

@@ -289,10 +289,10 @@ typedef struct {
 
 typedef struct {
     PyObject_HEAD
-    HMAC_CTX *ctx;      /* OpenSSL hmac context */
+    HMAC_CTX *ctx;            /* OpenSSL hmac context */
     // Prevents undefined behavior via multiple threads entering the C API.
     bool use_mutex;
-    PyMutex mutex;      /* HMAC context lock */
+    PyMutex mutex; /* HMAC context lock */
 } HMACobject;
 
 #define HMACobject_CAST(op) ((HMACobject *)(op))