avoid integer overflow

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@51468 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.watershed/ram/do_cum.c

@@ -7,7 +7,8 @@
 int do_cum(void)
 {
     int r, c, dr, dc;
-    CELL is_swale, value, valued, aspect;
+    CELL is_swale, aspect;
+    DCELL value, valued;
     int killer, threshold, count;
     int asp_r[9] = { 0, -1, -1, -1, 0, 1, 1, 1, 0 };
     int asp_c[9] = { 0, 1, 0, -1, -1, -1, 0, 1, 1 };