Add minor fix to BMC MAC update tool

This fix is to take a new Connection post BMC reboot.

Change-Id: Ia8b6753fedf2a3c57345b15637d9927388facb6d
Signed-off-by: Sunil M <sunilmam@us.ibm.com>
diff --git a/lib/bmc_network_utils.robot b/lib/bmc_network_utils.robot
index 231fbff..9a7a12c 100644
--- a/lib/bmc_network_utils.robot
+++ b/lib/bmc_network_utils.robot
@@ -37,6 +37,9 @@
 
     Write  fw_setenv ethaddr ${mac_address}
     OBMC Reboot (off)
+
+    # Take SSH session post BMC reboot.
+    Open Connection And Log In
     ${bmc_mac_addr}=  Execute Command On BMC  cat /sys/class/net/eth0/address
     Should Be Equal  ${bmc_mac_addr}  ${mac_address}  ignore_case=True