[ALSA] Fix synchronize_irq() bugs, redundancies

free_irq() calls synchronize_irq() for you, so there is no need for
drivers to manually do the same thing (again).  Thus, calls where
sync-irq immediately precedes free-irq can be simplified.

However, during this audit several bugs were noticed, where free-irq is
preceded by a "irq >= 0" check... but the sync-irq call is not covered
by the same check.

So, where sync-irq could not be eliminated completely, the missing check
was added.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/intel8x0m.c b/sound/pci/intel8x0m.c
index cadda8d..15db810 100644
--- a/sound/pci/intel8x0m.c
+++ b/sound/pci/intel8x0m.c
@@ -986,7 +986,8 @@
 	for (i = 0; i < chip->bdbars_count; i++)
 		iputbyte(chip, ICH_REG_OFF_CR + chip->ichd[i].reg_offset, ICH_RESETREGS);
 	/* --- */
-	synchronize_irq(chip->irq);
+	if (chip->irq >= 0)
+		synchronize_irq(chip->irq);
       __hw_end:
 	if (chip->bdbars.area)
 		snd_dma_free_pages(&chip->bdbars);