storage: Implementing a quick fix for the storage benchwrapper where reads error out early due to r.Remain being unknown (-1).

Change-Id: I4d5ccec33b098b5546ae90435397cf92cb778ce4
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/48870
Reviewed-by: Jean de Klerk <deklerk@google.com>
Reviewed-by: kokoro <noreply+kokoro@google.com>
diff --git a/storage/internal/benchwrapper/main.go b/storage/internal/benchwrapper/main.go
index dba1637..0817a31 100644
--- a/storage/internal/benchwrapper/main.go
+++ b/storage/internal/benchwrapper/main.go
@@ -74,7 +74,7 @@
 		return nil, err
 	}
 	defer r.Close()
-	for int(r.Remain()) > 0 {
+	for r.Remain() > 0 || r.Remain() == -1 {
 		ba := make([]byte, minRead)
 		_, err := r.Read(ba)
 		if err == io.EOF {