Update location of gnxi files due to docker-ptf modification (#5574)

What is the motivation for this PR?
PR sonic-net/sonic-buildimage#10599 move the work directory to /root.
So gnxi is moved to /root. test_telemetry failed because of wrong file location.

How did you do it?
Update /gnxi/... to /root/gnxi/...

How did you verify/test it?
run tests/telemetry/test_telemetry.py

Signed-off-by: Zhaohui Sun <zhaohuisun@microsoft.com>

tests/telemetry/test_telemetry.py

@@ -60,7 +60,7 @@ def setup_telemetry_forpyclient(duthost):
 def generate_client_cli(duthost, method=METHOD_GET, xpath="COUNTERS/Ethernet0", target="COUNTERS_DB", subscribe_mode=SUBSCRIBE_MODE_STREAM, submode=SUBMODE_SAMPLE, intervalms=0, update_count=3):
     """Generate the py_gnmicli command line based on the given params.
     """
-    cmdFormat = 'python /gnxi/gnmi_cli_py/py_gnmicli.py -g -t {0} -p {1} -m {2} -x {3} -xt {4} -o {5}'
+    cmdFormat = 'python /root/gnxi/gnmi_cli_py/py_gnmicli.py -g -t {0} -p {1} -m {2} -x {3} -xt {4} -o {5}'
     cmd = cmdFormat.format(duthost.mgmt_ip, TELEMETRY_PORT, method, xpath, target, "ndastreamingservertest")
 
     if method == METHOD_SUBSCRIBE:
@@ -101,7 +101,7 @@ def setup_streaming_telemetry(duthosts, rand_one_dut_hostname, localhost,  ptfho
     wait_tcp_connection(localhost, dut_ip, TELEMETRY_PORT, timeout_s=60)
 
     # pyclient should be available on ptfhost. If it was not available, then fail pytest.
-    file_exists = ptfhost.stat(path="/gnxi/gnmi_cli_py/py_gnmicli.py")
+    file_exists = ptfhost.stat(path="/root/gnxi/gnmi_cli_py/py_gnmicli.py")
     pytest_assert(file_exists["stat"]["exists"] is True)
 
 def skip_201911_and_older(duthost):
@@ -160,7 +160,7 @@ def test_telemetry_ouput(duthosts, rand_one_dut_hostname, ptfhost, setup_streami
 
     logger.info('start telemetry output testing')
     dut_ip = duthost.mgmt_ip
-    cmd = 'python /gnxi/gnmi_cli_py/py_gnmicli.py -g -t {0} -p {1} -m get -x COUNTERS/Ethernet0 -xt COUNTERS_DB \
+    cmd = 'python /root/gnxi/gnmi_cli_py/py_gnmicli.py -g -t {0} -p {1} -m get -x COUNTERS/Ethernet0 -xt COUNTERS_DB \
            -o "ndastreamingservertest"'.format(dut_ip, TELEMETRY_PORT)
     show_gnmi_out = ptfhost.shell(cmd)['stdout']
     logger.info("GNMI Server output")
@@ -191,7 +191,7 @@ def test_sysuptime(duthosts, rand_one_dut_hostname, ptfhost, setup_streaming_tel
     duthost = duthosts[rand_one_dut_hostname]
     skip_201911_and_older(duthost)
     dut_ip = duthost.mgmt_ip
-    cmd = 'python /gnxi/gnmi_cli_py/py_gnmicli.py -g -t {0} -p {1} -m get -x proc/uptime -xt OTHERS \
+    cmd = 'python /root/gnxi/gnmi_cli_py/py_gnmicli.py -g -t {0} -p {1} -m get -x proc/uptime -xt OTHERS \
            -o "ndastreamingservertest"'.format(dut_ip, TELEMETRY_PORT)
     system_uptime_info = ptfhost.shell(cmd)["stdout_lines"]
     system_uptime_1st = 0