Bug-1180: Added segment-routing errors.

-"Non-identical ERO subobject" and "Bad label value"
ref.:https://tools.ietf.org/html/draft-sivabalan-pce-segment-routing-02#section-9.2

Change-Id: I64c6a79de1367e34d826834bfc7a0fe623413754
Signed-off-by: Milos Fabian <milfabia@cisco.com>