[gegl] matrix: use non-doc comment for gegl_matrix2_determinant()

[N/A <ell src gnome org>]

commit efbae14ef6919e0f1b86b4193f5043b452ede844
Author: Ell <ell_se yahoo com>
Date:   Sat Mar 3 12:30:35 2018 -0500

    matrix: use non-doc comment for gegl_matrix2_determinant()
    
    GeglMatrix2 is internal for now.

 gegl/gegl-matrix.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gegl/gegl-matrix.h b/gegl/gegl-matrix.h
index b080a1f..b1a110f 100644
--- a/gegl/gegl-matrix.h
+++ b/gegl/gegl-matrix.h
@@ -32,7 +32,7 @@ typedef struct {
     gdouble coeff[2][2];
 } GeglMatrix2;
 
-/**
+/*
  * gegl_matrix2_determinant:
  * @matrix: a #GeglMatrix2
  *