cogl-shader: correctly #ifdef guard an if else block

There are quite a few if {} else {} blocks for dealing with arbfp else
glsl and the first block is guarded with #ifdef HAVE_COGL_GL. In this
case though the #endif was before the else so it wouldn't compile for
gles.

cogl/cogl-shader.c

@@ -129,8 +129,8 @@ cogl_shader_source (CoglHandle   handle,
           g_free (shader->arbfp_source);
           shader->arbfp_source = NULL;
         }
-#endif
       else
+#endif
         {
           if (shader->gl_handle)
             GE (glDeleteShader (shader->gl_handle));