gpu: Remove unused arguments

It's not just unused, it's also wrong.

We are reading from the buffer when reallocating the vertex buffer
and memcpy()ing the old into the new buffer - at that point we read from
it.

gsk/gpu/gskglbuffer.c

@@ -8,7 +8,6 @@ struct _GskGLBuffer
 
   GLenum target;
   GLuint buffer_id;
-  GLenum access;
   guchar *data;
 };
 
@@ -66,8 +65,7 @@ gsk_gl_buffer_init (GskGLBuffer *self)
 
 GskGpuBuffer *
 gsk_gl_buffer_new (GLenum target,
-                   gsize  size,
-                   GLenum access)
+                   gsize  size)
 {
   GskGLBuffer *self;
 
@@ -76,7 +74,6 @@ gsk_gl_buffer_new (GLenum target,
   gsk_gpu_buffer_setup (GSK_GPU_BUFFER (self), size);
 
   self->target = target;
-  self->access = access;
 
   glGenBuffers (1, &self->buffer_id);
   glBindBuffer (target, self->buffer_id);

gsk/gpu/gskglbufferprivate.h

@@ -11,8 +11,7 @@ G_BEGIN_DECLS
 G_DECLARE_FINAL_TYPE (GskGLBuffer, gsk_gl_buffer, GSK, GL_BUFFER, GskGpuBuffer)
 
 GskGpuBuffer *          gsk_gl_buffer_new                               (GLenum                  target,
-                                                                         gsize                   size,
-                                                                         GLenum                  access);
+                                                                         gsize                   size);
 
 void                    gsk_gl_buffer_bind                              (GskGLBuffer            *self);
 void                    gsk_gl_buffer_bind_base                         (GskGLBuffer            *self,

gsk/gpu/gskglframe.c

@@ -147,14 +147,14 @@ gsk_gl_frame_create_vertex_buffer (GskGpuFrame *frame,
    */
   g_hash_table_remove_all (self->vaos);
 
-  return gsk_gl_buffer_new (GL_ARRAY_BUFFER, size, GL_WRITE_ONLY);
+  return gsk_gl_buffer_new (GL_ARRAY_BUFFER, size);
 }
 
 static GskGpuBuffer *
 gsk_gl_frame_create_storage_buffer (GskGpuFrame *frame,
                                     gsize        size)
 {
-  return gsk_gl_buffer_new (GL_UNIFORM_BUFFER, size, GL_WRITE_ONLY);
+  return gsk_gl_buffer_new (GL_UNIFORM_BUFFER, size);
 }
 
 static void