qapi: Sort qapi-schema tests

qapi: Sort qapi-schema tests

Recent changes to qapi have provided quite a bit of churn in
the makefile, because we are inconsistent on what order test
names appear in, and on whether to re-wrap the list of tests or
just add arbitrary line lengths.  Writing the list in a sorted
fashion, one test per line, will make future patches easier
to see what tests are being added or removed by a patch.

Although it is tempting to use $(wildcard qapi-schema/*.json)
for a more compact listing, such an approach would risk picking
up leftover garbage .json files in the directory; so keeping
the list explicit is safer for ensuring reproducible tarballs
and test results.

Signed-off-by: Eric Blake <[email protected]>
Message-Id: <1443565276[email protected]>
Signed-off-by: Markus Armbruster <[email protected]>