Added the missing xpath for power button

Change-Id: Ib922da6343d65185cfd48e173fcc616ce8c373b2
Signed-off-by: Rahul Maheshwari <rahulmaheshwari@in.ibm.com>
diff --git a/gui/test/server_control/test_obmc_gui_server_power_operations.robot b/gui/test/server_control/test_obmc_gui_server_power_operations.robot
index a74ac30..0dc8578 100644
--- a/gui/test/server_control/test_obmc_gui_server_power_operations.robot
+++ b/gui/test/server_control/test_obmc_gui_server_power_operations.robot
@@ -13,7 +13,7 @@
 ${xpath_power_indicator_bar}     //*[@id='power-indicator-bar']
 ${xpath_shutdown_button}         //button[contains(text(), "Shut down")]
 ${xpath_reboot_button}           //button[contains(text(), "Reboot")]
-
+${xpath_power_on_button}         //button[contains(text(), "Power on")]
 
 *** Test Cases ***