cr: Remove --snapshot from help text

It's not complete and is about to change significantly. Better not
show it oficially.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

crtools.c

@@ -366,10 +366,9 @@ usage:
 	pr_msg("  -t|--tree             checkpoint/restore the whole process tree identified by pid\n");
 	pr_msg("  -d|--restore-detached detach after restore\n");
 	pr_msg("  -s|--leave-stopped    leave tasks in stopped state after checkpoint instead of killing them\n");
-	pr_msg("  -R|--leave-running    leave tasks in running state after checkpoint (useful with --snapshot)\n");
+	pr_msg("  -R|--leave-running    leave tasks in running state after checkpoint\n");
 	pr_msg("  -D|--images-dir       directory where to put images to\n");
 	pr_msg("     --pidfile [FILE]	write a pid of a root task in this file\n");
-	pr_msg("     --snapshot <[DIR]> create snapshot (relative to DIR images if given) (for 'dump' command)\n");
 
 	pr_msg("\n* Special resources support:\n");
 	pr_msg("  -x|--%s      allow external unix connections\n", USK_EXT_PARAM);