changing vec4 to vec2 for perf reasons.

Change-Id: Ic885a6dc697af4fd82e184158772863673f041bd
diff --git a/libs/rs/rsProgramFragment.cpp b/libs/rs/rsProgramFragment.cpp
index c94f294..81b4fa4 100644
--- a/libs/rs/rsProgramFragment.cpp
+++ b/libs/rs/rsProgramFragment.cpp
@@ -190,7 +190,7 @@
 {
     String8 shaderString(RS_SHADER_INTERNAL);
     shaderString.append("varying lowp vec4 varColor;\n");
-    shaderString.append("varying vec4 varTex0;\n");
+    shaderString.append("varying vec2 varTex0;\n");
     shaderString.append("void main() {\n");
     shaderString.append("  lowp vec4 col = UNI_Color;\n");
     shaderString.append("  gl_FragColor = col;\n");