Fixed const-correctness for BulletAllHitRayResult.

panda/src/bullet/bulletAllHitsRayResult.cxx

@@ -156,7 +156,7 @@ get_hit_fraction() const {
 //       Access: Published
 //  Description:
 ////////////////////////////////////////////////////////////////////
-PandaNode *BulletRayHit::
+const PandaNode *BulletRayHit::
 get_node() const {
 
   return (_object) ? (PandaNode *)_object->getUserPointer() : NULL;

panda/src/bullet/bulletAllHitsRayResult.h

@@ -33,7 +33,7 @@ struct EXPCL_PANDABULLET BulletRayHit {
 PUBLISHED:
   INLINE static BulletRayHit empty();
 
-  PandaNode *get_node() const;
+  const PandaNode *get_node() const;
   LPoint3 get_hit_pos() const;
   LVector3 get_hit_normal() const;
   PN_stdfloat get_hit_fraction() const;