drm/panel: sharp-lq101r1sx01: Fixed reversed "if" in remove

Commit d7d473d8 ("drm/panel: sharp-lq101r1sx01: Don't call disable
at shutdown/remove") had a subtle bug. We should be calling
sharp_panel_del() when the "sharp" variable is non-NULL, not when it's
NULL. Fix.

Fixes: d7d473d8

 ("drm/panel: sharp-lq101r1sx01: Don't call disable at shutdown/remove")
Cc: Thierry Reding <treding@nvidia.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202406261525.SkhtM3ZV-lkp@intel.com/
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240708105221.1.I576751c661c7edb6b804dda405d10e2e71153e32@changeid