test: Remove code dependency for mi test

test: Remove code dependency for mi test

When generating th coverage report, lcov chokes on the '../src/nvme'
paths prefix:

  geninfo: WARNING: GCOV did not produce any data for /home/wagi/work/libnvme-upstream/obj/src/test-mi.p/.._test_mi.c.gcda

We could restructure the project layout, e.g. by moving the test/mi.c
file to the src/nvme direcotry. But that looks ugly and as it turns
out we only really need one function copied over
nvme_mi_crc32_update() to resolve the dependency. The other function
is nvme_mi_init_ep() which we can easily open code.

Obviously, it would be better to fix the path issue for lcov but for
the time being let's go with this.

Signed-off-by: Daniel Wagner <dwagner@suse.de>