commit 34d8815f ("checkpatch: add --showfile to allow input via pipe
to show filenames") broke the --emacs with --file option.

Fix it.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>