drm/i915: Fix memory leaks in i915 selftests

This patch fixes memory leaks on error escapes in function fake_get_pages

Fixes: c3bfba9 ("drm/i915: Check for integer truncation on scatterlist creation")
Signed-off-by: Cong Liu <liucong2@kylinos.cn>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230414224109.1051922-1-andi.shyti@linux.intel.com
(cherry picked from commit 8bfbdad)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Author: Cong Liu

drivers/gpu/drm/i915/selftests/i915_gem_gtt.c

@@ -69,8 +69,10 @@ static int fake_get_pages(struct drm_i915_gem_object *obj)
 
 	rem = round_up(obj->base.size, BIT(31)) >> 31;
 	/* restricted by sg_alloc_table */
-	if (overflows_type(rem, unsigned int))
+	if (overflows_type(rem, unsigned int)) {
+		kfree(pages);
 		return -E2BIG;
+	}
 
 	if (sg_alloc_table(pages, rem, GFP)) {
 		kfree(pages);