git reset --hard include/linux/config.h

While working on something unrelated I just did a quick hack
in include/linux/config.h
When done I wanted to get rid of the changes so I did:
git reset --hard include/linux/config.h

And the changes made to include/linux/config.h was indeed gone, with
all the other changes I had in other files.

Now git reset is maybe supposed to work on commit level only, but it
would have been nice if it erroroed out when it saw an argument that
it did not know about. In this case I assume git reset used
"include/linux/config.h" as <commitish>.

Also what is the right command to bring back a file to the original
state after doing some modifications that was not needed anyway?

	Sam