drm: xlnx: zynqmp_dpsub: Fix compilation error

Fix W=1 clang 19 compilation error in zynqmp_disp_layer_drm_formats().

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404260946.4oZXvHD2-lkp@intel.com/

Signed-off-by: Anatoliy Klymenko <anatoliy.klymenko@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Fixes: b0f0469 ("drm: xlnx: zynqmp_dpsub: Anounce supported input formats")
Link: https://patchwork.freedesktop.org/patch/msgid/20240426-dp-live-fmt-fix-v3-2-e904b5ae51d7@amd.com
(cherry picked from commit c722117)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Author: Anatoliy Klymenko

drivers/gpu/drm/xlnx/zynqmp_disp.c

@@ -981,7 +981,7 @@ u32 *zynqmp_disp_layer_drm_formats(struct zynqmp_disp_layer *layer,
 	unsigned int i;
 	u32 *formats;
 
-	if (WARN_ON(!layer->mode == ZYNQMP_DPSUB_LAYER_NONLIVE)) {
+	if (WARN_ON(layer->mode != ZYNQMP_DPSUB_LAYER_NONLIVE)) {
 		*num_formats = 0;
 		return NULL;
 	}