drm/msm: Fix inverted WARN_ON() logic

We want to WARN_ON() if info is NULL.

Suggested-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Fixes: 0838fc3e ("drm/msm/adreno: Check for recognized GPU before bind")
Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
Reported-by: Alexey Klimov <alexey.klimov@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/658631/