USB: EHCI: adjust ehci_iso_stream for changes in ehci_qh

The EHCI driver stores in usb_host_endpoint.hcpriv a pointer to either
an ehci_qh or an ehci_iso_stream structure, and uses the contents of the
hw_info1 field to distinguish the two cases.

After ehci_qh was split into hw and sw parts, ehci_iso_stream must also
be adjusted so that it again looks like an ehci_qh structure.

This fixes a NULL pointer access in ehci_endpoint_disable() when it
tries to access qh->hw->hw_info1.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Reported-by: Colin Fletcher <colin.m.fletcher@googlemail.com>
Cc: stable <stable@kernel.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index cd1e8bf..a0aaaaf 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1123,8 +1123,8 @@
 					urb->interval);
 		}
 
-	/* if dev->ep [epnum] is a QH, info1.maxpacket is nonzero */
-	} else if (unlikely (stream->hw_info1 != 0)) {
+	/* if dev->ep [epnum] is a QH, hw is set */
+	} else if (unlikely (stream->hw != NULL)) {
 		ehci_dbg (ehci, "dev %s ep%d%s, not iso??\n",
 			urb->dev->devpath, epnum,
 			usb_pipein(urb->pipe) ? "in" : "out");