BUILD: ebtree: make eb_is_empty() and eb_is_dup() take a const

For whatever absurd reason these ones do not take a const, resulting in
some haproxy functions being forced to confusingly use variables instead
of const arguments. Let's fix this and backport it to older versions.

(cherry picked from commit 43be340a0e4d9194ea06514d8d5cfb6964381dfc)
[wt: dependency for next patch]
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed