drm/i915: Don't call sg_free_table() if sg_alloc_table() fails

One needs to call __sg_free_table() if __sg_alloc_table() fails, but
sg_alloc_table() does that for us already.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewd-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6131305..f21a0c3 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1774,7 +1774,6 @@
 
 	page_count = obj->base.size / PAGE_SIZE;
 	if (sg_alloc_table(st, page_count, GFP_KERNEL)) {
-		sg_free_table(st);
 		kfree(st);
 		return -ENOMEM;
 	}