Fixed pools golint warnings for go1.7

Signed-off-by: Lei Jitang <[email protected]>

Author: coolljt0725

utils/pools.go

@@ -46,10 +46,10 @@ func init() {
 // newBufioReaderPoolWithSize is unexported because new pools should be
 // added here to be shared where required.
 func newBufioReaderPoolWithSize(size int) *BufioReaderPool {
-	pool := sync.Pool{
+	pool := &sync.Pool{
 		New: func() interface{} { return bufio.NewReaderSize(nil, size) },
 	}
-	return &BufioReaderPool{pool: pool}
+	return &BufioReaderPool{pool: *pool}
 }
 
 // Get returns a bufio.Reader which reads from r. The buffer size is that of the pool.
@@ -65,14 +65,6 @@ func (bufPool *BufioReaderPool) Put(b *bufio.Reader) {
 	bufPool.pool.Put(b)
 }
 
-// Copy is a convenience wrapper which uses a buffer to avoid allocation in io.Copy.
-func Copy(dst io.Writer, src io.Reader) (written int64, err error) {
-	buf := BufioReader32KPool.Get(src)
-	written, err = io.Copy(dst, buf)
-	BufioReader32KPool.Put(buf)
-	return
-}
-
 // BufioWriterPool is a bufio writer that uses sync.Pool.
 type BufioWriterPool struct {
 	pool sync.Pool
@@ -81,10 +73,10 @@ type BufioWriterPool struct {
 // newBufioWriterPoolWithSize is unexported because new pools should be
 // added here to be shared where required.
 func newBufioWriterPoolWithSize(size int) *BufioWriterPool {
-	pool := sync.Pool{
+	pool := &sync.Pool{
 		New: func() interface{} { return bufio.NewWriterSize(nil, size) },
 	}
-	return &BufioWriterPool{pool: pool}
+	return &BufioWriterPool{pool: *pool}
 }
 
 // Get returns a bufio.Writer which writes to w. The buffer size is that of the pool.