all: simplify nested complexity and if blocks ending with a return statement (#21854)

Changes:

    Simplify nested complexity
    If an if blocks ends with a return statement then remove the else nesting.

Most of the changes has also been reported in golint https://goreportcard.com/report/github.com/ethereum/go-ethereum#golint

les/lespay/server/balance.go

@@ -588,9 +588,8 @@ func (n *NodeBalance) timeUntil(priority int64) (time.Duration, bool) {
 			}
 			dt = float64(posBalance-newBalance) / timePrice
 			return time.Duration(dt), true
-		} else {
-			dt = float64(posBalance) / timePrice
 		}
+		dt = float64(posBalance) / timePrice
 	} else {
 		if priority > 0 {
 			return 0, false

les/lespay/server/balance_tracker.go

@@ -261,9 +261,8 @@ func (bt *BalanceTracker) storeBalance(id []byte, neg bool, value utils.ExpiredV
 func (bt *BalanceTracker) canDropBalance(now mclock.AbsTime, neg bool, b utils.ExpiredValue) bool {
 	if neg {
 		return b.Value(bt.negExp.LogOffset(now)) <= negThreshold
-	} else {
-		return b.Value(bt.posExp.LogOffset(now)) <= posThreshold
 	}
+	return b.Value(bt.posExp.LogOffset(now)) <= posThreshold
 }
 
 // updateTotalBalance adjusts the total balance after executing given callback.

les/lespay/server/prioritypool.go

@@ -288,9 +288,8 @@ func activePriority(a interface{}, now mclock.AbsTime) int64 {
 	}
 	if c.bias == 0 {
 		return invertPriority(c.nodePriority.Priority(now, c.capacity))
-	} else {
-		return invertPriority(c.nodePriority.EstMinPriority(now+mclock.AbsTime(c.bias), c.capacity, true))
 	}
+	return invertPriority(c.nodePriority.EstMinPriority(now+mclock.AbsTime(c.bias), c.capacity, true))
 }
 
 // activeMaxPriority callback returns estimated maximum priority of ppNodeInfo item in activeQueue