Use -Werror in frameworks/native/opengl/libagl

* Remove unused local variables and functions.

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Ib8e3ee6e3c1ee3cf1e26f265fc87890f1690c6a2
diff --git a/opengl/libagl/array.cpp b/opengl/libagl/array.cpp
index 54207fa..2d36c61 100644
--- a/opengl/libagl/array.cpp
+++ b/opengl/libagl/array.cpp
@@ -136,9 +136,6 @@
 static void currentColor(ogles_context_t* c, GLfixed* v, const GLvoid*) {
     memcpy(v, c->current.color.v, sizeof(vec4_t));
 }
-static void currentColor_clamp(ogles_context_t* c, GLfixed* v, const GLvoid*) {
-    memcpy(v, c->currentColorClamped.v, sizeof(vec4_t));
-}
 static void currentNormal(ogles_context_t* c, GLfixed* v, const GLvoid*) {
     memcpy(v, c->currentNormal.v, sizeof(vec3_t));
 }
@@ -349,6 +346,7 @@
 {
     // make sure the size of vertex_t allows cache-line alignment
     CTA<(sizeof(vertex_t) & 0x1F) == 0> assertAlignedSize;
+    (void)assertAlignedSize; // suppress unused warning.
 
     const int align = 32;
     const size_t s = VERTEX_BUFFER_SIZE + VERTEX_CACHE_SIZE;