Fix build of document

Error introduced in 59cd205 "VIRTIO-98: Add DEVICE_NEEDS_RESET":
seems that underscores in labels are verboten:

[133] [134] (./virtio-v1.0-csprd02.aux
! Missing \endcsname inserted.
<to be read again>
                   \unhbox
l.45 ...ts: Device Status Field}}{subsection.1}{}}

Signed-off-by: Rusty Russell <rusty@au1.ibm.com>

git-svn-id: https://tools.oasis-open.org/version-control/svn/virtio@373 0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652

content.tex

@@ -73,7 +73,7 @@ \section{\field{Device Status} Field}\label{sec:Basic Facilities of a Virtio Dev
 
 The device MUST NOT consume buffers or notify the driver before DRIVER_OK.
 
-\label{sec:Basic Facilities of a Virtio Device / Device Status Field / DEVICE_NEEDS_RESET}The device SHOULD set DEVICE_NEEDS_RESET when it enters an error state
+\label{sec:Basic Facilities of a Virtio Device / Device Status Field / DEVICENEEDSRESET}The device SHOULD set DEVICE_NEEDS_RESET when it enters an error state
 that a reset is needed.  After it sets DEVICE_NEEDS_RESET, the device
 MUST send a device configuration change notification to the driver.
 
@@ -919,7 +919,7 @@ \subsection{Notification of Device Configuration Changes}\label{sec:General Init
 interrupt is delivered when a device-specific configuration change occurs.
 
 In addition, this interrupt is triggered by the device setting
-DEVICE_NEEDS_RESET (see \ref{sec:Basic Facilities of a Virtio Device / Device Status Field / DEVICE_NEEDS_RESET}).
+DEVICE_NEEDS_RESET (see \ref{sec:Basic Facilities of a Virtio Device / Device Status Field / DEVICENEEDSRESET}).
 
 \section{Device Cleanup}\label{sec:General Initialization And Device Operation / Device Cleanup}