Use a local variable to find SSEU runtime information
in various debugfs functions.

v2: Remove extra line breaks per feedback from Chris
Signed-off-by: NStuart Summers <stuart.summers@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190823160307.180813-2-stuart.summers@intel.com