Fix broadcast MAC address verification

This change includes:
    1. Logic to get actual MAC address.

Resolves openbmc/openbmc-test-automation#1150

Change-Id: I3c5cde03741b5fca2951b468807d33ef77394f3f
Signed-off-by: Prashanth Katti <prkatti1@in.ibm.com>
diff --git a/lib/bmc_network_utils.robot b/lib/bmc_network_utils.robot
index fbc5c6f..39c7cc9 100644
--- a/lib/bmc_network_utils.robot
+++ b/lib/bmc_network_utils.robot
@@ -93,7 +93,13 @@
 
     ${cmd_output}=  Execute Command On BMC  /sbin/ip addr | grep ether
 
-    [Return]  ${cmd_output}
+    # Split the line and return MAC address.
+    # Split list data:
+    # link/ether | xx:xx:xx:xx:xx:xx | brd | ff:ff:ff:ff:ff:ff
+
+    @{words}=  Split String  ${cmd_output}
+
+    [Return]  ${words[1]}
 
 Get BMC Hostname
     [Documentation]  Get BMC hostname.