commit 09a5c34e upstream.

GCC reports a -Wlogical-not-parentheses warning here; therefore
add parentheses to shut it up and to express our intent more.
Signed-off-by: James C Boyd <jcboyd.dev@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>