drm/i915/scaler: Fix condition for WA_14011503117

As scaler_state can never be null so no need to
check this, only check if scaler_id is less
than 0 or not.

v2: Add scaler_id check [Jani]
v3: Modify commit message[Suraj]

Fixes: 73309ed9 ("drm/i915/display: WA_14011503117")
Signed-off-by: Nemesa Garg <nemesa.garg@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://lore.kernel.org/r/20250807113855.3175435-1-nemesa.garg@intel.com