Use __sysret() to shrink most of the library routines to oneline code.

Removed 266 lines of duplicated code.
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>