ide/isa: Replace unchecked qdev_init() by qdev_init_nofail()

isa_ide_init()'s callers don't check for failure.  isa_ide_init()
looks like it could fail, but since isa_ide_realizefn() can't fail, it
actually can't.  Replace its qdev_init() by qdev_init_nofail() to make
it obvious.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/hw/ide/isa.c b/hw/ide/isa.c
index b084162..c0c4e1b 100644
--- a/hw/ide/isa.c
+++ b/hw/ide/isa.c
@@ -88,9 +88,7 @@
     qdev_prop_set_uint32(dev, "iobase",  iobase);
     qdev_prop_set_uint32(dev, "iobase2", iobase2);
     qdev_prop_set_uint32(dev, "irq",     isairq);
-    if (qdev_init(dev) < 0) {
-        return NULL;
-    }
+    qdev_init_nofail(dev);
 
     s = ISA_IDE(dev);
     if (hd0) {