verify: fix verify issues with norandommap

verify: fix verify issues with norandommap

When norandommap is enabled, fio logs the I/O entries in a RB tree. This
is to account for offset overlaps and overwrites. Then during verify
phase, the I/O entries are picked from the top and in this case the
smallest offset is verified first and so on. This creates a mismatch
during the header verification as the seed generated at the time of read
differs from what was logged during write. Skip seed verification in
this scenario.

fixes #1756

Signed-off-by: Ankit Kumar <ankit.kumar@samsung.com>