drm/xe/stolen: switch from BUG_ON() to WARN_ON() in compat

We're pretty much never supposed to be using BUG_ON(). Switch to
WARN_ON().

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://lore.kernel.org/r/d14c693a3387a5d89bb88e81349639b5ec5663fb.1758732183.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/xe/compat-i915-headers/gem/i915_gem_stolen.h

@@ -51,7 +51,8 @@ static inline int i915_gem_stolen_insert_node(struct xe_device *xe,
 					      u32 size, u32 align)
 {
 	/* Not used on xe */
-	BUG_ON(1);
+	WARN_ON(1);
+
 	return -ENODEV;
 }