Drop "cpath" under -c (no file creation)

Index: truncate.c
--- truncate.c.orig
+++ truncate.c
@@ -84,6 +84,10 @@ main(int argc, char **argv)
 	argv += optind;
 	argc -= optind;
 
+	if (no_create)
+		if (pledge("stdio rpath wpath", NULL) == -1)
+			err(1, "pledge");
+
 	/*
 	 * Exactly one of do_refer or got_size must be specified.  Since
 	 * do_relative implies got_size, do_relative and do_refer are
