Cleanup: move trailing comments to avoid wrapping code

Some statements were split across multiple lines because of their
trailing comments.

In most cases it's clearer to put the comments above.

source/blender/gpu/GPU_vertex_buffer.h

@@ -87,9 +87,10 @@ void GPU_vertbuf_data_len_set(GPUVertBuf *, uint v_len);
  * should not be a problem. */
 
 void GPU_vertbuf_attr_set(GPUVertBuf *, uint a_idx, uint v_idx, const void *data);
-void GPU_vertbuf_attr_fill(GPUVertBuf *,
-                           uint a_idx,
-                           const void *data); /* tightly packed, non interleaved input data */
+
+/* Tightly packed, non interleaved input data. */
+void GPU_vertbuf_attr_fill(GPUVertBuf *, uint a_idx, const void *data);
+
 void GPU_vertbuf_attr_fill_stride(GPUVertBuf *, uint a_idx, uint stride, const void *data);
 
 /* For low level access only */