Fix reported anti patterns (#7501)

* merge var decl

* single append

* replace bytes.Compare -> bytes.Equal

* remove redundant spritnf

* remove redundant spritnf

* trimprefix

* remove redundant nil check

* remove redundant return

* plain channel or unblock on context closing

Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

beacon-chain/sync/initial-sync/blocks_fetcher_test.go

@@ -311,6 +311,9 @@ func TestBlocksFetcher_RoundRobin(t *testing.T) {
 						}
 
 						wg.Done()
+					case <-ctx.Done():
+						log.Debug("Context closed, exiting goroutine")
+						return unionRespBlocks, nil
 					}
 				}
 			}