Revert "Cache generated ids to relieve pressure on the GC"

It wasn't working as noticed by @rade (note the err != nil) and was complicating
the code.

This reverts commit 2f760f2f33.

report/id.go

@@ -1,13 +1,8 @@
 package report
 
 import (
-	"hash"
-	"hash/fnv"
 	"net"
 	"strings"
-	"sync"
-
-	"github.com/bluele/gcache"
 )
 
 // TheInternet is used as a node ID to indicate a remote IP.
@@ -29,38 +24,9 @@ const (
 	DoesNotMakeConnections = "does_not_make_connections"
 )
 
-var (
-	idCache = gcache.New(1024).LRU().Build()
-	hashers = sync.Pool{
-		New: func() interface{} {
-			return fnv.New64a()
-		},
-	}
-)
-
-func lookupID(part1, part2, part3 string, f func() string) string {
-	h := hashers.Get().(hash.Hash64)
-	h.Write([]byte(part1))
-	h.Write([]byte(part2))
-	h.Write([]byte(part3))
-	sum := h.Sum64()
-	var result string
-	if id, err := idCache.Get(sum); id != nil && err != nil {
-		result = id.(string)
-	} else {
-		result = f()
-		idCache.Set(sum, result)
-	}
-	h.Reset()
-	hashers.Put(h)
-	return result
-}
-
 // MakeEndpointNodeID produces an endpoint node ID from its composite parts.
 func MakeEndpointNodeID(hostID, address, port string) string {
-	return lookupID(hostID, address, port, func() string {
-		return MakeAddressNodeID(hostID, address) + ScopeDelim + port
-	})
+	return MakeAddressNodeID(hostID, address) + ScopeDelim + port
 }
 
 // MakeAddressNodeID produces an address node ID from its composite parts.