Description: Fix concatenation of storage_mode string.
Forwarded: not-needed
--- a/runtime/image.cc
+++ b/runtime/image.cc
@@ -191,7 +191,7 @@ bool ImageHeader::Block::Decompress(uint8_t* out_ptr,
     }
     default: {
       if (error_msg != nullptr) {
-        *error_msg = (std::ostringstream() << "Invalid image format " << storage_mode_).str();
+        *error_msg = "Invalid image format " + storage_mode_;
       }
       return false;
     }