usbip: Use _FORTIFY_SOURCE=2 instead of (implicitly) =1

usbip: Use _FORTIFY_SOURCE=2 instead of (implicitly) =1

Forwarded: https://lore.kernel.org/linux-usb/20230503173622.1072787-1-ukleinek@debian.org/

_FORTIFY_SOURCE=2 uses more and stricter checks. This is what e.g.
Debian recommends to build packages with.

While at it fix a typo in the output of ./configure --help.

Signed-off-by: Uwe Kleine-König <ukleinek@debian.org>
Reviewed-By: Hongren Zheng <i@zenithal.me>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name usbip_use__fortify_source_2_instead_of_implicitly_1.patch