run-xfstest.zsh: Remove xml file of previous run before starting

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

run-xfstests.zsh

@@ -18,6 +18,7 @@ export RESULT_BASE=/home/${USER[-1]}/xfstests-dev/results/${PROTO[-1]}/${VERSION
 mkdir -p $TEST_DIR
 mkdir -p $SCRATCH_MNT
 [ -e local.config ] && rm -f local.config
+[ -e $RESULT_BASE/result.xml ] && rm -f $RESULT_BASE/result.xml
 
 echo "TIME          -- $(date)"
 echo "TEST_DEV      -- $TEST_DEV"