testsuite: use ARRAY_SIZE() for iteration

testsuite: use ARRAY_SIZE() for iteration

Currently we use a mix of ARRAY_SIZE() and iterator pointer, where the
latter needs an extra instance for the NULL sentinel. Plus as evidenced
by the EXIT_SUCCESS -> EXIT_FAILURE changes in test-new-module - is
error prone.

Consistently use ARRAY_SIZE(), fixing the logical error in the test
which was flagged by ASan as memory leak :-)

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/371
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>