Skipping USB Interface From Valid Channel Number List.

Changes in lib/bmc_network_utils.robot
- In lib/bmc_network_utils.robot file on "Get Channel Number For Valid Ethernet Interface" keyword
added condition to skip the usb interface while taking valid channel number list.

Tested:
- Tested ipmi/test_ipmi_cipher.robot
- Tested ipmi/test_ipmi_general.robot
- Tested ipmi/test_ipmi_payload.robot
- Tested ipmi/test_ipmi_user.robot

Signed-off-by: ganesanb <ganesanb@ami.com>
Change-Id: I6d0f5c2c10d0e18b5ff142d3822e0223b9501cef
diff --git a/lib/bmc_network_utils.robot b/lib/bmc_network_utils.robot
index 2ece501..b904c81 100644
--- a/lib/bmc_network_utils.robot
+++ b/lib/bmc_network_utils.robot
@@ -725,6 +725,8 @@
     @{channel_number_list}=  Create List
 
     FOR  ${channel_number}  ${values}  IN  &{valid_channel_number_interface_name}
+      ${usb_interface_status}=  Run Keyword And Return Status  Should Not Contain  ${values['name']}  usb
+      Continue For Loop IF  ${usb_interface_status} == False
       Run Keyword If  '${values['channel_info']['medium_type']}' == 'lan-802.3'
       ...  Append To List  ${channel_number_list}  ${channel_number}
     END