GMPLS update - 22: updating mpls-interface statistics parameters agent mapper routines

#Updated #mpls-interface #statistics parameters agent routines in GMPLS module. The agent #iterator routines and #mapper #routine has been updated to use standard #mpls-interface #based #indexing. This will access the mpls-interface statistics embedded in the mpls-interface and there by removing the redundant indexing. The mpls-interface statistics entries holds the attributes like the #count of #in-coming and #out-going labels in use, count of #in-coming #label #look-up #failures, count of #out-going #fragmented #packets, etc ... The mpls-interface statistics entries are linked in to the mpls-interface create / remove API, so as to create the statistics entries on creating / removing the respective standard mpls-interface.

#GMPLS update 22 ...
[commit eb329e374915b16801e57ff4886df01a0a6499b0] (https://github.com/nes-repo/NES-Open-Switch/commit/eb329e374915b16801e57ff4886df01a0a6499b0)