rc: fix rc/uploadfile only working for root of the fs

fs/operations/rc.go

@@ -6,6 +6,7 @@ import (
 	"mime"
 	"mime/multipart"
 	"net/http"
+	"path"
 	"strings"
 	"time"
 
@@ -253,7 +254,7 @@ func rcSingleCommand(ctx context.Context, in rc.Params, name string, noRemote bo
 					return nil, err
 				}
 				if p.FileName() != "" {
-					obj, err := Rcat(ctx, f, p.FileName(), p, time.Now())
+					obj, err := Rcat(ctx, f, path.Join(remote, p.FileName()), p, time.Now())
 					if err != nil {
 						return nil, err
 					}