Add documentation for linux-sandbox -H option.
RELNOTES: None
@@ -65,6 +65,7 @@ static void Usage(char *program_name, const char *fmt, ...) {
"mounted readonly.\n"
" The -M option specifies which directory to mount, the -m option "
"specifies where to\n"
+ " -H if set, make hostname in the sandbox equal to 'localhost'\n"
" -N if set, a new network namespace will be created\n"
" -R if set, make the uid/gid be root\n"
" -U if set, make the uid/gid be nobody\n"
