depmod: fix debug print parameter order
Add test for simple search order in depmod
depmod: do not allow partial matches with "search" directive

Currently e.g. "search foo foobar built-in" will cause unpredictable
results if baz.ko is in both foo/ and foobar/, since "foo" in search may
match both of those directories and the preferred module therefore
depends on processing order.

Fix the code to ensure that the match is performed on full pathname
components only.
Add test for depmod using search dirs with same prefix

Test depmod with search dirs "foo" and "foobar". Previously to 49b33c1
("depmod: do not allow partial matches with "search" directive") we were
failing this test due to matching the prefix without checking if
it's the full dir name.

We are adding 2 tests here in order to catch the case we only pass the
test due to processing the directories in a favourable order.