Fix RenderScript warnings.

b/21443340

Change-Id: I09fcab70a17658febf23de874e15edfcfd5f94f3
diff --git a/src/com/android/phasebeam/phasebeam.rs b/src/com/android/phasebeam/phasebeam.rs
index 037f303..ccbf60a 100644
--- a/src/com/android/phasebeam/phasebeam.rs
+++ b/src/com/android/phasebeam/phasebeam.rs
@@ -89,7 +89,6 @@
         particle++;
     }
 
-    Particle_t* beam = beamParticles;
     numBeamParticles = rsAllocationGetDimX(rsGetAllocation(beamParticles));
     for(int i=0; i<numBeamParticles; i++) {
         float z;