drm/i915/selftests: Initialise ret

Keep smatch quiet,

drivers/gpu/drm/i915//gem/selftests/i915_gem_context.c:1268 __igt_ctx_sseu() error: uninitialized symbol 'ret'.
drivers/gpu/drm/i915//gem/selftests/i915_gem_context.c:1280 __igt_ctx_sseu() error: uninitialized symbol 'ret'.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191028142652.1987-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c

@@ -1188,7 +1188,7 @@ __igt_ctx_sseu(struct drm_i915_private *i915,
 {
 	struct drm_i915_gem_object *obj;
 	int inst = 0;
-	int ret;
+	int ret = 0;
 
 	if (INTEL_GEN(i915) < 9 || !RUNTIME_INFO(i915)->sseu.has_slice_pg)
 		return 0;