From: Jiamu Sun <barroit@linux.com>

executing `git bugreport --no-suffix` led to a segmentation fault
due to strbuf_addftime() being called with a NULL option_suffix
variable. This occurs because negating the "--[no-]suffix" option
causes the parser to set option_suffix to NULL, which is not
handled prior to calling strbuf_addftime().

Signed-off-by: Jiamu Sun <barroit@linux.com>

Submitted-As: https://lore.kernel.org/git/pull.1693.git.1710260812280.gitgitgadget@gmail.com