libsegment: do not zero fill, use lseek in Segment_open()

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@73268 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/segment/open.c

@@ -66,7 +66,7 @@ Segment_open(SEGMENT *SEG, char *fname, off_t nrows, off_t ncols,
 	G_warning(_("Unable to create segment file"));
 	return -1;
     }
-    if (0 > (ret = Segment_format(SEG->fd, nrows, ncols, srows,
+    if (0 > (ret = Segment_format_nofill(SEG->fd, nrows, ncols, srows,
 							scols, len))) {
 	close(SEG->fd);
 	unlink(SEG->fname);