GUACAMOLE-1114: Merge fix the destruction of some thread mutexes

diff --git a/src/common/clipboard.c b/src/common/clipboard.c
index e02a7ca..227623e 100644
--- a/src/common/clipboard.c
+++ b/src/common/clipboard.c
@@ -46,7 +46,14 @@
 }
 
 void guac_common_clipboard_free(guac_common_clipboard* clipboard) {
+
+    /* Destroy lock */
+    pthread_mutex_destroy(&(clipboard->lock));
+
+    /* Free buffer */
     free(clipboard->buffer);
+
+    /* Free base structure */
     free(clipboard);
 }
 
diff --git a/src/protocols/rdp/print-job.c b/src/protocols/rdp/print-job.c
index 5a75c6e..7d711c0 100644
--- a/src/protocols/rdp/print-job.c
+++ b/src/protocols/rdp/print-job.c
@@ -631,6 +631,9 @@
     /* Wait for job to terminate */
     pthread_join(job->output_thread, NULL);
 
+    /* Destroy lock */
+    pthread_mutex_destroy(&(job->state_lock));
+
     /* Free base structure */
     free(job);