comment out icon_load()

As suggested, altought icon_load() is not used to build this example/canvas.c,
it might still be useful. So instead of deleting, the function is now commented.

example/canvas.c

@@ -77,6 +77,29 @@ die(const char *fmt, ...)
     exit(EXIT_FAILURE);
 }
 
+/* function icon_load () is not used in this file but might be useful :) */
+/*
+static struct nk_image	
+icon_load(const char *filename)	
+{	
+    int x,y,n;	
+    GLuint tex;	
+    unsigned char *data = stbi_load(filename, &x, &y, &n, 0);	
+    if (!data) die("[SDL]: failed to load image: %s", filename);	
+
+     glGenTextures(1, &tex);	
+    glBindTexture(GL_TEXTURE_2D, tex);	
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);	
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR_MIPMAP_NEAREST);	
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);	
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);	
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, x, y, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);	
+    glGenerateMipmap(GL_TEXTURE_2D);	
+    stbi_image_free(data);	
+    return nk_image_id((int)tex);	
+}
+*/
+
 static void
 device_init(struct device *dev)
 {