drm/amd/display: Run DC_LOG_DC after checking link->link_enc

[WHAT]
The DC_LOG_DC should be run after link->link_enc is checked, not before.

This fixes 1 REVERSE_INULL issue reported by Coverity.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>