ASoC: dapm: Fix source list debugfs outputs

commit ff18620c upstream.

... due to a copy & paste error.

Spotted by coverity CID 710923.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>