BUILD: ebtree: fix build on libmusl after recent introduction of eb_memcmp()

In order to address a corner case with memory compares, commit 853926a
("BUG/MEDIUM: ebtree: use a byte-per-byte memcmp() to compare memory
blocks") introduced a new eb_memcmp() function, which uses ssize_t for
an offset. However this one is not known by default in ebtree for versions
prior to 2.2, and it depends on the libs. Musl requires unistd to be included
to have it.

This patch just adds this harmless include, which was verified to address
issue #760. There is no mainline commit ID as 2.2 and above already include
unistd.h as part of haproxy/api.h. It must be backported to older versions
(2.0 already has the commit above).

(cherry picked from commit c926085c7e01a93e326e8081f466d23304767a36)
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed