build.sh: fix a couple of typos.
build.sh: fix a couple of typos.

Fix one typo and changed one error message to be consistent
    with other very similar messages. No logic change.

Signed-off-by: Peter Hutterer <b9c50af7afa7642f6f854434cda9ffe54ece8b85@who-t.net>

tmzt/androix-util-modular,freedesktop-unofficial-mirror/xorg__util__modular,freedesktop-unofficial-mirror/xorg__util__modular,tmzt/androix-util-modular,freedesktop-unofficial-mirror/xorg__util__modular