LU-13933 tests: remove some unnecessary back-slashes.

LU-13933 tests: remove some unnecessary back-slashes.

Various scripts use "\ " where the "\" isn't needed.

In an 'awk' pattern, using "\ " is wrong.
In the arg to 'tr', there is no need to '\' a space.

In shell code, <<" foo ">> is easier to read than <<\ foo\ >>.

Also:

In shell code <<name="value">> can be <<name=value>> if <<value>>
doesn't contain unquoted spaces.  If value does contain quoted <<">>,
the extra quotes make it hard to read.

Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I53d0522071016286b4ef9f576f4a4e46b1ba2d6d
Reviewed-on: https://review.whamcloud.com/39750
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>