*: fix all comment-related golint warnings

Some of this code is going to be moved to SDK library, so it's important.

Signed-off-by: Roman Khimov <roman@nspcc.ru>

connections/pool.go

@@ -15,6 +15,7 @@ import (
 	"google.golang.org/grpc/keepalive"
 )
 
+// PoolBuilderOptions contains options used to build connection pool.
 type PoolBuilderOptions struct {
 	Key                     *ecdsa.PrivateKey
 	NodeConnectionTimeout   time.Duration
@@ -28,17 +29,21 @@ type PoolBuilderOptions struct {
 	connections             []*grpc.ClientConn
 }
 
+// PoolBuilder is an interim structure used to collect node addresses/weights and
+// build connection pool subsequently.
 type PoolBuilder struct {
 	addresses []string
 	weights   []float64
 }
 
+// AddNode adds address/weight pair to node PoolBuilder list.
 func (pb *PoolBuilder) AddNode(address string, weight float64) *PoolBuilder {
 	pb.addresses = append(pb.addresses, address)
 	pb.weights = append(pb.weights, weight)
 	return pb
 }
 
+// Build creates new pool based on current PoolBuilder state and options.
 func (pb *PoolBuilder) Build(ctx context.Context, options *PoolBuilderOptions) (Pool, error) {
 	if len(pb.addresses) == 0 {
 		return nil, errors.New("no NeoFS peers configured")
@@ -75,6 +80,7 @@ func (pb *PoolBuilder) Build(ctx context.Context, options *PoolBuilderOptions) (
 	return new(ctx, options)
 }
 
+// Pool is an interface providing connection artifacts on request.
 type Pool interface {
 	ConnectionArtifacts() (client.Client, *token.SessionToken, error)
 }