client: Replace apistatus type check with error check

Signed-off-by: Evgenii Baidakov <evgenii@nspcc.io>

client/status/status.go

@@ -1,5 +1,9 @@
 package apistatus
 
+import (
+	"errors"
+)
+
 // Status defines a variety of NeoFS API status returns.
 //
 // All statuses are split into two disjoint subsets: successful and failed, and:
@@ -22,7 +26,7 @@ type Status any
 // Note: direct assignment may not be compatibility-safe.
 func ErrFromStatus(st Status) error {
 	if err, ok := st.(error); ok {
-		return err
+		return errors.Join(Error, err)
 	}
 
 	return nil

client/status/status_test.go

@@ -19,7 +19,7 @@ func TestErrors(t *testing.T) {
 
 		res := apistatus.ErrFromStatus(st)
 
-		require.Equal(t, err, res)
+		require.ErrorIs(t, res, err)
 	})
 
 	t.Run("non-error source", func(t *testing.T) {

pool/pool.go

@@ -992,11 +992,10 @@ func (c *clientStatusMonitor) handleError(st apistatus.Status, err error) error
 	}
 
 	err = apistatus.ErrFromStatus(st)
-	switch err.(type) {
-	case apistatus.ServerInternal, *apistatus.ServerInternal,
-		apistatus.WrongMagicNumber, *apistatus.WrongMagicNumber,
-		apistatus.SignatureVerification, *apistatus.SignatureVerification,
-		apistatus.NodeUnderMaintenance, *apistatus.NodeUnderMaintenance:
+	if errors.Is(err, apistatus.ErrServerInternal) ||
+		errors.Is(err, apistatus.ErrWrongMagicNumber) ||
+		errors.Is(err, apistatus.ErrSignatureVerification) ||
+		errors.Is(err, apistatus.ErrNodeUnderMaintenance) {
 		c.incErrorRate()
 	}