Free the allocated memory in lzmadec if debugging is

enabled. This should make it possible to detect possible
memory leaks with Valgrind.

src/lzmadec/lzmadec.c

@@ -513,5 +513,12 @@ main(int argc, char **argv)
 		} while (++optind < argc);
 	}
 
+#ifndef NDEBUG
+	// Free the memory only when debugging. Freeing wastes some time,
+	// but allows detecting possible memory leaks with Valgrind.
+	lzma_end(&strm);
+	lzma_memlimit_end(mem_limitter, false);
+#endif
+
 	return exit_status;
 }