ALSA: asihpi: Deletion of an unnecessary check before the function call "vfree"

The vfree() function performs also input parameter validation. Thus the test
around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/asihpi/hpioctl.c b/sound/pci/asihpi/hpioctl.c
index e457eb8..6aa677e 100644
--- a/sound/pci/asihpi/hpioctl.c
+++ b/sound/pci/asihpi/hpioctl.c
@@ -547,8 +547,7 @@
 	if (pa->irq)
 		free_irq(pa->irq, pa);
 
-	if (pa->p_buffer)
-		vfree(pa->p_buffer);
+	vfree(pa->p_buffer);
 
 	if (1)
 		dev_info(&pci_dev->dev,