drm/i915/error: Capture WA ctx batch in error state

execute during context save/restore, good to have them in error state.

v2: use wa_ctx->size and print only size values (Mika)
v3: simplify conditions when recording and freeing object (Chris)
v4: resolve checkpatch errors (Tvrtko)

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456831476-10782-1-git-send-email-arun.siluvery@linux.intel.com
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6712955..7d2b07f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -561,6 +561,8 @@
 			u32 *pages[0];
 		} *ringbuffer, *batchbuffer, *wa_batchbuffer, *ctx, *hws_page;
 
+		struct drm_i915_error_object *wa_ctx;
+
 		struct drm_i915_error_request {
 			long jiffies;
 			u32 seqno;