[tests] [asan] extend graceful stop flag to also stop syncd (#2491)

- What I did
Extended DVS test "--graceful-stop" flag to also stop syncd.

- Why I did it
So ASAN can generate reports for syncd.

- How I verified it
Run the tests with --graceful-stop, observe that the syncd process is stopped via SIGTERM

Signed-off-by: Yakiv Huryk <yhuryk@nvidia.com>

tests/conftest.py

@@ -92,7 +92,7 @@ def pytest_addoption(parser):
     parser.addoption("--graceful-stop",
                      action="store_true",
                      default=False,
-                     help="Stop swss before stopping a conatainer")
+                     help="Stop swss and syncd before stopping a conatainer")
 
 
 def random_string(size=4, chars=string.ascii_uppercase + string.digits):
@@ -670,6 +670,10 @@ def stop_swss(self):
         self.runcmd(['sh', '-c', cmd])
         time.sleep(5)
 
+    def stop_syncd(self):
+        self.runcmd(['sh', '-c', 'supervisorctl stop syncd'])
+        time.sleep(5)
+
     # deps: warm_reboot
     def start_zebra(self):
         self.runcmd(['sh', '-c', 'supervisorctl start zebra'])
@@ -1792,6 +1796,7 @@ def update_dvs(log_path, new_dvs_env=[]):
 
     if graceful_stop:
         dvs.stop_swss()
+        dvs.stop_syncd()
     dvs.get_logs()
     dvs.destroy()