Fix the bugs in hwpoison related test cases

Fix two bugs in two test cases.
1) In the test for disk file soft off-line, it often fails
because it is mmaped via shared mode. Now chaning it
to private mode to fix wider test environment.

2) in run_soft.sh there is one spell mistake so that some
test case will fail.

Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>