drm/msm/dp: Remove unused variable

Kernel test roobot throws below warning ->

drivers/gpu/drm/msm/dp/dp_display.c:1017:21:
warning: variable 'drm' set but not used [-Wunused-but-set-variable]

Removed unused variable drm.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Link: https://lore.kernel.org/r/20210709024834.29680-1-jrdr.linux@gmail.comReviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/dp/dp_display.c

@@ -1008,10 +1008,8 @@ int dp_display_get_test_bpp(struct msm_dp *dp)
 void msm_dp_snapshot(struct msm_disp_state *disp_state, struct msm_dp *dp)
 {
 	struct dp_display_private *dp_display;
-	struct drm_device *drm;
 
 	dp_display = container_of(dp, struct dp_display_private, dp_display);
-	drm = dp->drm_dev;
 
 	/*
 	 * if we are reading registers we need the link clocks to be on