Fix attribute name

BMC web is case sensitive, so making the change.

Change-Id: Ia8d6979aba1d2c3cd5fd922ac4186c246e4922b5
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/lib/esel_utils.robot b/lib/esel_utils.robot
index d6ac800..7f079b8 100755
--- a/lib/esel_utils.robot
+++ b/lib/esel_utils.robot
@@ -53,7 +53,7 @@
     #       "Severity": "xyz.openbmc_project.Logging.Entry.Level.Error",
     #       "Timestamp": 1485904869061
     # }
-    ${entry_id}=  Read Attribute  ${elog_entry[0]}  message
+    ${entry_id}=  Read Attribute  ${elog_entry[0]}  Message
     Should Be Equal  ${entry_id}
     ...  org.open_power.Host.Error.Event