I have needed to disclose certain property defects that have become apparent as a result of the previous inspection and in that case I will use portions of that inspection as verification of the same to the new buyer. However, if the new buyer wants the full report in order to save their own money/time in lieu of having a new home inspection done I usually contact the previous buyer's agent to see if their client would like to sell the home inspection to the new buyer (usually at a discounted rate). This seems to work out well for all the parties involved.
Often, I do not have a full copy of the home inspection in the file as the previous buyer's agent only sent along those portions of the inspection that were pertaining to the defects that were written up in the Inspection Notice from the buyers. That is, normally, what I send along to the seller's agent when I have the buyers - not the full report.