Closes-Bug: #1400162
-Issue: In 14.0.4, storage stats Subprocess Popen
  returns the following warning on all calls:
  "['libust[38153/38153]: Warning: HOME environment
   variable not set. Disabling LTTng-UST per-user
   tracing. (in setup_local_apps() at
   lttng-ust-comm.c:305)"
-Fix: copied current environment variables and
      added "HOME" variable. This newly created
      environment is then passed to Popen call
      to solve the above mentioned issue
-Test: Verified the changes on HA cluster

Change-Id: Id6b82536fa539347739cdf1ab0c836689915b3da
Merge "Closes-Bug: #1400162 -Issue: In 14.0.4, storage stats Subprocess Popen   returns the following warning on all calls:   "['libust[38153/38153]: Warning: HOME environment    variable not set. Disabling LTTng-UST per-user    tracing. (in setup_local_apps() at    lttng-ust-comm.c:305)" -Fix: copied current environment variables and       added "HOME" variable. This newly created       environment is then passed to Popen call       to solve the above mentioned issue -Test: Verified the changes on HA cluster" into R2.0