drm/amd/display: Move desync error counter operation up.

[Why & How]
Move desync error counter operation up to prevent
it from being skipped by force disable desync
error.

Reviewed-by: Robin Chen <robin.chen@amd.com>
Reviewed-by: Aric Cyr <aric.cyr@amd.com>
Signed-off-by: Jack Chang <jack.chang@amd.com>
Signed-off-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
Tested-by: Mark Broadworth <mark.broadworth@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>