CP-6167: Fix a bug reported by pylint
CP-6167: Fix a bug reported by pylint

_mklink is not a class method hence shouldn't have referenced 'cls'.
Use 'self' instead.

Signed-off-by: Zheng Li <fff69bf00b8ec5b6098a1768eaaaa75f40b8795d@eu.citrix.com>

djs55/sm,chandrikas/sm,chandrikas/sm,malcolmcrossley/sm,robertbreker/sm,siddharthv/sm,kostaslamda/sm,BobBall/sm,djs55/sm,djs55/sm,kostaslamda/sm,martinjorge/sm,xapi-project/sm,malcolmcrossley/sm,pritha-srivastava/sm,pritha-srivastava/sm,xapi-project/sm,malcolmcrossley/sm,BobBall/sm,geosharath/sm,chandrikas/sm,martinjorge/sm,geosharath/sm,germanop/sm,germanop/sm,robertbreker/sm,BobBall/sm,geosharath/sm,germanop/sm,pritha-srivastava/sm,kostaslamda/sm,siddharthv/sm,xapi-project/sm,robertbreker/sm,martinjorge/sm,siddharthv/sm