format-code: call linters by file types

Revamp the format-code script to only look at git-managed files,
so that we don't need to worry about subproject exclusions, and
classify affected files based on their file type.  Allow linters
to specify the file types they are applicable to and call each
applicable linter with the explicit files, rather than allowing
the linter programs to do directory traversals (which causes problems
in some cases).

Tested: I have ran this against every active repository in Gerrit to
ensure I don't break any existing repositories with this change.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I70ac6de1f9925ccd35396c894b45f16e33884551
1 file changed