vcs-svn: use mark from previous import for parent commit

With this patch, overlapping incremental imports work.

Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

vcs-svn/fast_export.c

@@ -83,7 +83,7 @@ void fast_export_begin_commit(uint32_t revision, uint32_t author, char *log,
 		   log, gitsvnline);
 	if (!first_commit_done) {
 		if (revision > 1)
-			printf("from refs/heads/master^0\n");
+			printf("from :%"PRIu32"\n", revision - 1);
 		first_commit_done = 1;
 	}
 }