Check for NULL before de-refencing; in particular sel is assigned to NULL,
in the default case, and then couple of lines down we do sel->

Approved by:	glebius (mentor)
Obtained from:	NetBSD CVS repo (r1.5)
Rename the tests to something more meaningful. I spent way too long
trying to get the test name right, failed, gave up and used a sequence
number instead. When I realized it wasn't because of the number of
underscores in the name that I really started to think. I didn't have
braces around the variable names ...

Thus: test_1 is now called apm_1x1_512_qcow, which gives you all you
need to run mkimg by hand.

Dumb-ass: marcel