A bluestore race condition is been fixed by protecting txc structures
within _txc_state_poc with collection lock.
Mark's comments:
This fixes segfaults during random write tests with bluestore.
This passes "ceph_test_objectstore --gtest_filter=*/2".
This may introduce a small performance regresion, though there is enough
noise in the results to make it inconclusive.
Closes #10220
Signed-off-by: Somnath Roy <somnath.roy@sandisk.com>