Test: avoid spurious failures in make test-network-all

Before running make test-network-all, delete old logs and test result
files, to avoid spurious failures.

Fixes bug 27295; bugfix on 0.2.7.3-rc.

Makefile.am

@@ -106,6 +106,7 @@ test-network: need-chutney-path $(TESTING_TOR_BINARY) src/tools/tor-gencert
 # Try both the BSD and the Linux ping6 syntax, because they're incompatible
 test-network-all: need-chutney-path test-driver $(TESTING_TOR_BINARY) src/tools/tor-gencert
 	mkdir -p $(TEST_NETWORK_ALL_LOG_DIR)
+	rm -f $(TEST_NETWORK_ALL_LOG_DIR)/*.log $(TEST_NETWORK_ALL_LOG_DIR)/*.trs
 	@flavors="$(TEST_CHUTNEY_FLAVORS)"; \
 	if ping6 -q -c 1 -o ::1 >/dev/null 2>&1 || ping6 -q -c 1 -W 1 ::1 >/dev/null 2>&1; then \
 		echo "ping6 ::1 succeeded, running IPv6 flavors: $(TEST_CHUTNEY_FLAVORS_IPV6)."; \

changes/bug27295

@@ -0,0 +1,3 @@
+  o Minor bugfixes (testing, chutney):
+    - Before running make test-network-all, delete old logs and test result
+      files, to avoid spurious failures. Fixes bug 27295; bugfix on 0.2.7.3-rc.