Cleanup: use colon separator after parameter

Helps separate variable names from descriptive text.
Was already used in some parts of the code,
double space and dashes were used elsewhere.

source/blender/python/mathutils/mathutils_Matrix.c

@@ -969,7 +969,7 @@ static void matrix_invert_with_det_n_internal(float *mat_dst, const float *mat_s
 }
 
 /**
- * \param r_mat can be from ``self->matrix`` or not.
+ * \param r_mat: can be from ``self->matrix`` or not.
  */
 static bool matrix_invert_internal(const MatrixObject *self, float *r_mat)
 {
@@ -988,7 +988,7 @@ static bool matrix_invert_internal(const MatrixObject *self, float *r_mat)
 
 /**
  * Similar to ``matrix_invert_internal`` but should never error.
- * \param r_mat can be from ``self->matrix`` or not.
+ * \param r_mat: can be from ``self->matrix`` or not.
  */
 static void matrix_invert_safe_internal(const MatrixObject *self, float *r_mat)
 {