Address review comments

Signed-off-by: a-palchikov <deemok@gmail.com>

client/solve.go

@@ -186,7 +186,7 @@ func (c *Client) solve(ctx context.Context, def *llb.Definition, runGateway runG
 				supportFile = ex.Output != nil
 			}
 			if supportFile && supportDir {
-				return nil, errors.Errorf("both file and directory output is not support by %s exporter", ex.Type)
+				return nil, errors.Errorf("both file and directory output is not supported by %s exporter", ex.Type)
 			}
 			if !supportFile && ex.Output != nil {
 				return nil, errors.Errorf("output file writer is not supported by %s exporter", ex.Type)
@@ -305,26 +305,18 @@ func (c *Client) solve(ctx context.Context, def *llb.Definition, runGateway runG
 			exports = append(exports, localExporter)
 		}
 
-		// For older server, use the first exporter
-		var ex ExportEntry
-		if len(opt.Exports) != 0 {
-			ex = opt.Exports[0]
-		}
-
 		resp, err := c.ControlClient().Solve(ctx, &controlapi.SolveRequest{
-			Ref:                     ref,
-			Definition:              pbd,
-			ExporterDeprecated:      ex.Type,
-			ExporterAttrsDeprecated: ex.Attrs,
-			Exporters:               exports,
-			Session:                 s.ID(),
-			Frontend:                opt.Frontend,
-			FrontendAttrs:           frontendAttrs,
-			FrontendInputs:          frontendInputs,
-			Cache:                   cacheOpt.options,
-			Entitlements:            opt.AllowedEntitlements,
-			Internal:                opt.Internal,
-			SourcePolicy:            opt.SourcePolicy,
+			Ref:            ref,
+			Definition:     pbd,
+			Exporters:      exports,
+			Session:        s.ID(),
+			Frontend:       opt.Frontend,
+			FrontendAttrs:  frontendAttrs,
+			FrontendInputs: frontendInputs,
+			Cache:          cacheOpt.options,
+			Entitlements:   opt.AllowedEntitlements,
+			Internal:       opt.Internal,
+			SourcePolicy:   opt.SourcePolicy,
 		})
 		if err != nil {
 			return errors.Wrap(err, "failed to solve")

solver/result/result.go

@@ -1,8 +1,6 @@
 package result
 
 import (
-	"sync"
-
 	"github.com/pkg/errors"
 )