Address new yaml format changes introduced by sdbusplus commit 7d7fda5

Patrick's commit for exceptions had a few tweaks to the yaml
file format.  This commit updates elog_gen.py to support them.

Change-Id: I59261ab0fddefde67304cbb394c74b9c9c5e496f
Signed-off-by: Andrew Geissler <andrewg@us.ibm.com>
diff --git a/tools/elog-gen.py b/tools/elog-gen.py
index c94e1b4..7f2448d 100755
--- a/tools/elog-gen.py
+++ b/tools/elog-gen.py
@@ -39,10 +39,10 @@
     # see elog.yaml for reference
     ifile = yaml.safe_load(open(i_elog_yaml))
     err_count = 0
-    for i in ifile['error-codes']:
+    for i in ifile:
         # Grab the main error and it's info
         errors[err_count] = i['name']
-        error_msg[i['name']] = i['msg']
+        error_msg[i['name']] = i['description']
         error_lvl[i['name']] = i['level']
         tmp_meta = []
         # grab all the meta data fields and info