Fixes coccicheck warning:

drivers/gpu/drm/amd/display/modules/hdcp/hdcp.c:506:2-3: Unneeded semicolon
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>