Add calling wc_FreeMutex for globalRNGMutex

src/ssl.c

@@ -13389,6 +13389,11 @@ int wolfSSL_Cleanup(void)
         ret = WC_CLEANUP_E;
     }
 
+#ifdef HAVE_GLOBAL_RNG
+    if (wc_FreeMutex(&globalRNGMutex) != 0) {
+        ret = BAD_MUTEX_E;
+    }
+#endif
     return ret;
 }