Fix sensor_id value in test_sensors_ipmi.robot
Fix sensor_id value in test_sensors_ipmi.robot

Very minor issues:
- In keyword "Check OperatingSystemState", ${Sensor_ID} is declared
as an argument but in the code at line 373 ${sensor_id} is used.
- Adjust formatting to conform to coding guidelines.

Resolves openbmc/openbmc-test-automation#1216

Change-Id: I6a5e64df0cbfe3ff4e1647a5a12bb5fcdb952930
Signed-off-by: Steven Sombar <fb37bb6ac5c2258e1cbf80690dea88925949957e@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation