drm/plane: Move range check for format_count earlier

While the check for format_count > 64 in __drm_universal_plane_init()
shouldn't be hit (it's a WARN_ON), in its current position it will then
leak the plane->format_types array and fail to call
drm_mode_object_unregister() leaking the modeset identifier. Move it to
the start of the function to avoid allocating those resources in the
first place.

Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://lore.kernel.org/dri-devel/20211203102815.38624-1-steven.price@arm.com/