session: remove trivial defaultCurve function

session/private.go

@@ -2,6 +2,7 @@ package session
 
 import (
 	"crypto/ecdsa"
+	"crypto/elliptic"
 	"crypto/rand"
 
 	crypto "github.com/nspcc-dev/neofs-crypto"
@@ -16,7 +17,7 @@ type pToken struct {
 //
 // Returns non-nil error on key generation error.
 func NewPrivateToken() (PrivateToken, error) {
-	sk, err := ecdsa.GenerateKey(defaultCurve(), rand.Reader)
+	sk, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
 	if err != nil {
 		return nil, err
 	}

session/store.go

@@ -1,7 +1,6 @@
 package session
 
 import (
-	"crypto/elliptic"
 	"sync"
 )
 
@@ -11,11 +10,6 @@ type mapTokenStore struct {
 	tokens map[TokenID]PrivateToken
 }
 
-// TODO get curve from neofs-crypto
-func defaultCurve() elliptic.Curve {
-	return elliptic.P256()
-}
-
 // NewMapTokenStore creates new PrivateTokenStore instance.
 //
 // The elements of the instance are stored in the map.