ALSA: asihpi - Make local function static

Fixes a sparse warning.

Signed-off-by: Eliot Blennerhassett <eblennerhassett@audioscience.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/asihpi/hpi6205.c b/sound/pci/asihpi/hpi6205.c
index 3c75df8..e041a6a 100644
--- a/sound/pci/asihpi/hpi6205.c
+++ b/sound/pci/asihpi/hpi6205.c
@@ -373,6 +373,7 @@
 /** Entry point to this HPI backend
  * All calls to the HPI start here
  */
+static
 void _HPI_6205(struct hpi_adapter_obj *pao, struct hpi_message *phm,
 	struct hpi_response *phr)
 {