The base versions handle constant folding just fine, use them
directly.  The replacements are OK in the include/ files as they are
not exported to userspace so we don't need the __ prefixed versions.

This patch does not affect code generation at all.
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>