fix assertion

src/plugin/pctrace.cpp

@@ -58,7 +58,7 @@ public:
 
 private:
     int_type overflow(int_type ch) override {
-        assert(pptr() <= epptr());
+        assert(pptr() > epptr());
         *pptr() = static_cast<char_type>(ch);
         pbump(1);
         compress_and_write();