set the type before doing the vmap so calls to cnam() will be set, avoiding
a double-falure case when vmap fails and then we indirect nil to get the
controler name.

Reference: /n/atom/patch/applied2013/ahcityporder
Date: Tue Sep 17 01:11:49 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/sdahci.c	Tue Sep 17 01:10:55 2013
+++ /sys/src/nix/k10/sdahci.c	Tue Sep 17 01:10:55 2013
@@ -1839,6 +1839,7 @@
 		s = sdevs + niactlr;
 		memset(c, 0, sizeof *c);
 		memset(s, 0, sizeof *s);
+		c->type = cttab + type;
 		io = p->mem[Abar].bar & ~0xf;
 		c->mmio = vmap(io, p->mem[Abar].size);
 		if(c->mmio == nil){
@@ -1848,7 +1849,6 @@
 		}
 		c->lmmio = (u32int*)c->mmio;
 		c->pci = p;
-		c->type = cttab + type;
 
 		s->ifc = &sdahciifc;
 		s->idno = 'E';