EX-2882 tests: fix hot-pools.sh issues on single node

EX-2882 tests: fix hot-pools.sh issues on single node

This patch fixes the following issues while running hot-pools.sh
on single node:
- sh: warning: here-document at line 0 delimited by end-of-file
  (wanted `EOF')
- lfs changelog_clear: cannot open '/dev/changelog-lustre-MDT0000':
  No such file or directory (2)

Lustre-commit: ab4a750a5138fa9710adc5f196ac820634628c4d
Lustre-change: https://review.whamcloud.com/42140

Test-Parameters: trivial testlist=hot-pools,hot-pools
Test-Parameters: trivial testgroup=review-dne-part-2

Change-Id: Ie259438c737c9ef4c1fd7148a6cc918177b8fb47
Signed-off-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-by: Li Xi <lixi@ddn.com>
Reviewed-on: https://review.whamcloud.com/43122
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>