tests: Remove hard-coding of lower bound

Problem:
Total blocks of XFS partition are dependent on XFS parameters used
for formatting. So hardcoded lower-bound may not be the lower bound
for different default parameters.

Used blocks are lesser on my machine for a freshly formatted XFS partition
compared to where the test fails.
On my machine:
Filesystem     1024-blocks  Used Available Capacity Mounted on
/dev/loop0           98980  5472     93508       6% /d/backends/patchy1
/dev/loop1           98980  5472     93508       6% /d/backends/patchy2

On a machine where this test fails:
Filesystem     1024-blocks  Used Available Capacity Mounted on
/dev/loop0           96928  6112     90816       7% /d/backends/patchy1
/dev/loop1           96928  6112     90816       7% /d/backends/patchy2

Fix:
Make lower bound 2% less than the brick-blocks available

fixes: bz#1761759
Change-Id: I974d5e75766f7ff44780a2e4c2a19cd5d1d14a79
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

0 files changed, 0 insertions, 0 deletions