Cleanup: remove redundant doxygen \file argument

Move \ingroup onto same line to be more compact and
make it clear the file is in the group.

source/blender/draw/engines/eevee/eevee_shaders.c

@@ -16,8 +16,7 @@
  * Copyright 2016, Blender Foundation.
  */
 
-/** \file eevee_shaders.c
- *  \ingroup draw_engine
+/** \file \ingroup draw_engine
  */
 
 #include "DRW_render.h"