2e: releasetools: be more clear about firmware image patching

This looks very odd on most of the devices using this tree
because nothing is being patched. Just mention which image
is being flashed and only when it actually is.

Change-Id: Ib6c35e08aee0f1c102da28ca37434093a92f7045
Signed-off-by: Akhil Narang <akhilnarang.1999@gmail.com>