overlay: Show power consumption without i915-pmu
overlay: Show power consumption without i915-pmu

The power metter was not showing up due to an erroneous check for a
failure to open the i915 perf interface.

Reported-by: Marius Vlad <6363ee2f6e8c765e50e90378777a2b9a43131db2@intel.com>
Signed-off-by: Chris Wilson <711c73f64afdce07b7e38039a96d2224209e9a6c@chris-wilson.co.uk>

mv0/intel-gpu-tools,mv0/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,mv0/intel-gpu-tools,mv0/intel-gpu-tools