Change lifespan constructor parameter type from int to float to match its declared type.

panda/src/particlesystem/pointParticle.cxx

@@ -24,7 +24,7 @@
 // Description : simple constructor
 ////////////////////////////////////////////////////////////////////
 PointParticle::
-PointParticle(int lifespan, bool alive) :
+PointParticle(float lifespan, bool alive) :
   BaseParticle(lifespan, alive) {
   set_oriented(false);
 }

panda/src/particlesystem/pointParticle.h

@@ -28,7 +28,7 @@
 ////////////////////////////////////////////////////////////////////
 class EXPCL_PANDAPHYSICS PointParticle : public BaseParticle {
 public:
-  PointParticle(int lifespan = 0, bool alive = false);
+  PointParticle(float lifespan = 0.0f, bool alive = false);
   PointParticle(const PointParticle &copy);
   virtual ~PointParticle();