Cleanup: ensure space after file named in headers

Add blank lines after file references to avoid them being interpreted as
doc-strings the following declarations.

source/blender/render/RE_bake.h

@@ -61,6 +61,7 @@ typedef struct BakeHighPolyData {
 } BakeHighPolyData;
 
 /* external_engine.c */
+
 bool RE_bake_has_engine(const struct Render *re);
 
 bool RE_bake_engine(struct Render *re,
@@ -74,6 +75,7 @@ bool RE_bake_engine(struct Render *re,
                     float result[]);
 
 /* bake.c */
+
 int RE_pass_depth(eScenePassType pass_type);
 
 bool RE_bake_pixels_populate_from_objects(struct Mesh *me_low,