test/mbuf: fix mbuf data content check

test/mbuf: fix mbuf data content check

When allocating a mbuf, its data content is most of the time zero'd but
nothing ensures this. This is especially wrong when building with
RTE_MALLOC_DEBUG, where data is poisoned to 0x6b on free.

This test reserves MBUF_TEST_DATA_LEN2 bytes in the mbuf data segment,
and sets this data to 0xcc.
Calling strlen(), the test may try to read more than MBUF_TEST_DATA_LEN2
which has been noticed when memory had been poisoned.

The mbuf data content is checked right after, so we can simply remove
strlen().

Fixes: 7b295dceea07 ("test/mbuf: add unit test cases")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>