[SPARK-15300] Fix writer lock conflict when remove a block

## What changes were proposed in this pull request?

A writer lock could be acquired when 1) create a new block 2) remove a block 3) evict a block to disk. 1) and 3) could happen in the same time within the same task, all of them could happen in the same time outside a task. It's OK that when someone try to grab the write block for a block, but the block is acquired by another one that has the same task attempt id.

This PR remove the check.

## How was this patch tested?

Updated existing tests.

Author: Davies Liu <davies@databricks.com>

Closes #13082 from davies/write_lock_conflict.