Convert CRYPTO_LOCK_DSO to new multi-threading API

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>

include/openssl/crypto.h

@@ -187,7 +187,6 @@ extern "C" {
 # define CRYPTO_LOCK_READDIR             24
 # define CRYPTO_LOCK_RSA_BLINDING        25
 # define CRYPTO_LOCK_MALLOC2             27
-# define CRYPTO_LOCK_DSO                 28
 # define CRYPTO_LOCK_DYNLOCK             29
 # define CRYPTO_LOCK_ENGINE              30
 # define CRYPTO_LOCK_UI                  31

include/openssl/dso.h

@@ -228,6 +228,7 @@ struct dso_st {
      * loaded.
      */
     char *loaded_filename;
+    CRYPTO_RWLOCK *lock;
 };
 
 DSO *DSO_new(void);