drm/amd/display: Fix variable deferencing before NULL check in edp_setup_replay()

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix variable deferencing before NULL check in edp_setup_replay() In edp_setup_replay(), 'struct dc *dc' & 'struct dmub_replay *replay' was dereferenced before the pointer 'link' & 'replay' NULL check. Fixes the below: drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_edp_panel_control.c:947 edp_setup_replay() warn: variable dereferenced before check 'link' (see line 933)