Fixed alpha variable declaration in SSAO Normal pass shader.Thanks to koris.

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@9341 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/core-effects/Common/MatDefs/SSAO/normal.frag

@@ -8,9 +8,9 @@ varying vec2 texCoord;
 
 void main(void)
 {
-
+    float alpha= 1.0;
     #ifdef DIFFUSEMAP_ALPHA
-        float alpha=texture2D(m_DiffuseMap,texCoord).a;
+        alpha=texture2D(m_DiffuseMap,texCoord).a;
     #endif
     gl_FragColor = vec4(normal.xy* 0.5 + 0.5,-normal.z* 0.5 + 0.5, alpha);