[bug report] drm/i915: Small compaction of the engine init code

[Dan Carpenter]

Hello Tvrtko Ursulin,

The patch a19d6ff29a82: "drm/i915: Small compaction of the engine
init code" from Jun 23, 2016, leads to the following static checker
warning:

	drivers/gpu/drm/i915/intel_lrc.c:1973 logical_render_ring_init()
	warn: passing freed memory 'engine'

drivers/gpu/drm/i915/intel_lrc.c
  1970  
  1971          ret = logical_ring_init(engine);
  1972          if (ret) {
  1973                  lrc_destroy_wa_ctx_obj(engine);

The problem is that logical_ring_init() frees "engine" on the error
path so this is a use after free.

  1974          }
  1975  
  1976          return ret;
  1977  }

regards,
dan carpenter