release.sh: Generate error for missing arguments
release.sh: Generate error for missing arguments

All three arguments are required.  Otherwise git-rev-list will abort the
script silently.

Signed-off-by: Dirk Wallenstein <0094b88488405ee50298c1549891ed49bcd7831f@t-online.de>
Reviewed-by: Dan Nicholson <2570c412b7cbb4203ff39baaca2bd49e72848226@gmail.com>
Signed-off-by: Julien Cristau <82c7ebd12259428dfee9dc86e69f3a9d6f3dccb9@debian.org>

freedesktop-unofficial-mirror/xorg__util__modular,freedesktop-unofficial-mirror/xorg__util__modular,freedesktop-unofficial-mirror/xorg__util__modular