treewide: remove redundant loop vars

Change-Id: I61bada9e3df38e6a94cd6c8fe2d0d8f3ba41c1af
Reviewed-on: https://review.monogon.dev/c/monogon/+/2955
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/node/core/rpc/peerinfo.go b/metropolis/node/core/rpc/peerinfo.go
index 9e9476d..6a8443b 100644
--- a/metropolis/node/core/rpc/peerinfo.go
+++ b/metropolis/node/core/rpc/peerinfo.go
@@ -20,7 +20,7 @@
 func (p Permissions) String() string {
 	var res []string
 
-	for k, _ := range p {
+	for k := range p {
 		res = append(res, k.String())
 	}