[gnumeric] Fix warning.

[Morten Welinder <mortenw src gnome org>]

commit 4a379625bf1283f56c2155ad0fe000bedbc0c477
Author: Morten Welinder <terra gnome org>
Date:   Wed Apr 29 14:05:56 2009 -0400

    Fix warning.
---
 src/position.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/position.c b/src/position.c
index 44405a9..5006722 100644
--- a/src/position.c
+++ b/src/position.c
@@ -323,7 +323,7 @@ void
 gnm_cellpos_init_cellref (GnmCellPos *res, GnmCellRef const *cell_ref,
 			  GnmCellPos const *pos, Sheet const *base_sheet)
 {
-	Sheet *sheet = eval_sheet (cell_ref->sheet, base_sheet);
+	Sheet const *sheet = eval_sheet (cell_ref->sheet, base_sheet);
 	gnm_cellpos_init_cellref_ss (res, cell_ref, pos,
 				     gnm_sheet_get_size (sheet));
 }