golint: fix warnings for pkg/policy/utils.go
golint: fix warnings for pkg/policy/utils.go

Fixes the following warnings

pkg/policy/utils.go:21:1: exported function SplitNodePath should have comment or be unexported
pkg/policy/utils.go:29:1: exported function JoinPath should have comment or be unexported

Related-to: #153 (Resolve golint warnings)
Signed-off-by: Alexander Alemayhu <e46fc836cca3acec03944314d1457c2ae6c68ef3@alemayhu.com>

scanf/cilium,scanf/cilium,eloycoto/cilium,mskarbek/cilium,mskarbek/cilium,tgraf/cilium,scanf/cilium,eloycoto/cilium,scanf/cilium,eloycoto/cilium,cilium-team/cilium,scanf/cilium,michi-covalent/cilium,cilium/cilium,eloycoto/cilium,tklauser/cilium,gumpt/cilium,gumpt/cilium,tklauser/cilium,tgraf/cilium,gumpt/cilium,michi-covalent/cilium,tgraf/cilium,gumpt/cilium,gumpt/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,tgraf/cilium,scanf/cilium,eloycoto/cilium,gumpt/cilium,tgraf/cilium,eloycoto/cilium,cilium-team/cilium,cilium/cilium,cilium/cilium,mskarbek/cilium,gumpt/cilium,mskarbek/cilium,eloycoto/cilium,tklauser/cilium,tklauser/cilium,tgraf/cilium,mskarbek/cilium,mskarbek/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,scanf/cilium