fix deadlock on disable due to intrdisable calling the interrupt
fn so it can assert that the interrupt function will never be called
after intrdisable returns

Reference: /n/atom/patch/applied2013/ahcidisable
Date: Sun Dec 29 14:36:42 CET 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/sdahci.c	Sun Dec 29 14:35:39 2013
+++ /sys/src/nix/k10/sdahci.c	Sun Dec 29 14:35:40 2013
@@ -1301,17 +1301,12 @@
 static int
 iadisable(SDev *s)
 {
-	char name[32];
 	Ctlr *c;
 
 	c = s->ctlr;
-	ilock(c);
+	c->enabled = 0;
 	ahcidisable(c->hba);
-	snprint(name, sizeof name, "%s (%s)", s->name, s->ifc->name);
-	print("missing the intrdisable because intrdisable is wierd\n");
 	intrdisable(c->vector);
-	c->enabled = 0;
-	iunlock(c);
 	return 1;
 }