RCA is When we are deleting the agent-id, hsflowd is referring for th…

…e eth0 interface and expecting samples in that interface. (sonic-net#9766)

(This is with the updated hsflowd , When you start hsflowd with no explicit agent-id configured, it will run an "election" to decide which IP address to adopt.)

tests/sflow/test_sflow.py

@@ -474,7 +474,7 @@ def testDelAgent(self, duthost, partial_ptf_runner):
         # Verify  whether the samples are received with previously configured agent ip
         partial_ptf_runner(
             polling_int=20,
-            agent_id=var['lo_ip'],
+            agent_id=var['mgmt_ip'],
             active_collectors="['collector0','collector1']")
 
     def testAddAgent(self, duthost, partial_ptf_runner):