format-code: handle all files are ignored by linter

If all the files applicable to a linter have been ignored, then
we should not call the linter since many executables fail if no
source files are given as arguments.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I014291d807b2ef6be7ec3c5a5d3e7a4ce1de3717
1 file changed