Remove deprecated io/ioutil (#15707)

internal/http/close.go

@@ -19,7 +19,6 @@ package http
 
 import (
 	"io"
-	"io/ioutil"
 )
 
 // DrainBody close non nil response with any response Body.
@@ -38,6 +37,6 @@ func DrainBody(respBody io.ReadCloser) {
 		// the same connection for future uses.
 		//  - http://stackoverflow.com/a/17961593/4465767
 		defer respBody.Close()
-		io.Copy(ioutil.Discard, respBody)
+		io.Copy(io.Discard, respBody)
 	}
 }

internal/http/server.go

@@ -21,16 +21,16 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
-	"io/ioutil"
 	"log"
 	"net"
 	"net/http"
+	"os"
 	"runtime/pprof"
 	"sync"
 	"sync/atomic"
 	"time"
 
-	humanize "github.com/dustin/go-humanize"
+	"github.com/dustin/go-humanize"
 )
 
 var (
@@ -154,7 +154,7 @@ func (srv *Server) Shutdown() error {
 		select {
 		case <-shutdownTimer.C:
 			// Write all running goroutines.
-			tmp, err := ioutil.TempFile("", "minio-goroutines-*.txt")
+			tmp, err := os.CreateTemp("", "minio-goroutines-*.txt")
 			if err == nil {
 				_ = pprof.Lookup("goroutine").WriteTo(tmp, 1)
 				tmp.Close()