Avoid useless "++" at the end of functions

Warnings found by the Clang Static Analyzer.
diff --git a/Objects/setobject.c b/Objects/setobject.c
index 48edad8..22243ea 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -612,9 +612,9 @@
         *u++ = '{';
         /* Omit the brackets from the listrepr */
         Py_UNICODE_COPY(u, PyUnicode_AS_UNICODE(listrepr)+1,
-                           PyUnicode_GET_SIZE(listrepr)-2);
+                           newsize-2);
         u += newsize-2;
-        *u++ = '}';
+        *u = '}';
     }
     Py_DECREF(listrepr);
     if (Py_TYPE(so) != &PySet_Type) {
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 4361908..309159c 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -6474,7 +6474,7 @@
         }
     }
     /* 0-terminate the output string */
-    *output++ = '\0';
+    *output = '\0';
     Py_XDECREF(exc);
     Py_XDECREF(errorHandler);
     return 0;