[v9_11] Make kasp2policy.py PyLint-clean
PyLint 2.9.5 reported the following errors:
contrib/kasp/kasp2policy.py:25:0: R0402: Use 'from ply import yacc' instead (consider-using-from-import)
contrib/kasp/kasp2policy.py:26:0: R0402: Use 'from ply import lex' instead (consider-using-from-import)
(cherry picked from commit 4e094113)
Edited by Michal Nowak