tools: ynl-gen: fix enum index in _decode_enum(..)

Remove wrong index adjustment, which is leftover from adding
support for sparse enums.
enum.entries_by_val() function shall not subtract the start-value, as
it is indexed with real enum value.

Fixes: c311aaa ("tools: ynl: fix enum-as-flags in the generic CLI")
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20230725101642.267248-2-arkadiusz.kubalewski@intel.com
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/net/ynl/lib/ynl.py

@@ -420,16 +420,16 @@ def _add_attr(self, space, name, value):
     def _decode_enum(self, rsp, attr_spec):
         raw = rsp[attr_spec['name']]
         enum = self.consts[attr_spec['enum']]
-        i = attr_spec.get('value-start', 0)
         if 'enum-as-flags' in attr_spec and attr_spec['enum-as-flags']:
+            i = 0
             value = set()
             while raw:
                 if raw & 1:
                     value.add(enum.entries_by_val[i].name)
                 raw >>= 1
                 i += 1
         else:
-            value = enum.entries_by_val[raw - i].name
+            value = enum.entries_by_val[raw].name
         rsp[attr_spec['name']] = value
 
     def _decode_binary(self, attr, attr_spec):