Don't decrement the reference counter twice when destroying dynamic

links.

crypto/cryptlib.c

@@ -242,7 +242,7 @@ void CRYPTO_destroy_dynlockid(int i)
 			}
 		else
 #endif
-			if (--(pointer->references) <= 0)
+			if (pointer->references <= 0)
 				{
 				sk_CRYPTO_dynlock_set(dyn_locks, i, NULL);
 				}
@@ -401,7 +401,7 @@ void CRYPTO_lock(int mode, int type, const char *file, int line)
 		struct CRYPTO_dynlock_value *pointer
 			= CRYPTO_get_dynlock_value(i);
 
-		if (pointer)
+		if (pointer && dynlock_lock_callback)
 			{
 			dynlock_lock_callback(mode, pointer, file, line);
 			}