r.mapcalc: fix wrong result when neighborhood modifier takes a cell above first (trunk, https://trac.osgeo.org/grass/changeset/68717, fixes https://trac.osgeo.org/grass/ticket/3067)

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@68769 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.mapcalc/map.c

@@ -160,7 +160,7 @@ static void *cache_get_raw(struct row_cache *cache, int row, int data_type)
 
     if (i >= 0 && i < cache->nrows) {
 	if (!sub->valid[i]) {
-	    read_row(cache->fd, sub->buf[i], row + i, data_type);
+	    read_row(cache->fd, sub->buf[i], row, data_type);
 	    sub->valid[i] = 1;
 	}
 	return sub->buf[i];