openbmctool_execute_command map py2/3 compatible

openbmctool_execute_command has a map command that works in py2 but
not py3.  Fixed by surrounding the whole expression with list().

Change-Id: I41d078828fb923c3f53928f032ae03a86dc81369
Signed-off-by: Michael Walsh <micwalsh@us.ibm.com>
diff --git a/lib/openbmctool_utils.py b/lib/openbmctool_utils.py
index 2ec836b..e845f3a 100755
--- a/lib/openbmctool_utils.py
+++ b/lib/openbmctool_utils.py
@@ -76,7 +76,8 @@
     # example, the user may have specified "fru status | head -n 2" which
     # would be broken into 2 list elements.  We will also break on ">"
     # (re-direct).
-    pipeline = map(str.strip, re.split(r' ([\|>]) ', str(command_string)))
+    pipeline = list(map(str.strip, re.split(r' ([\|>]) ',
+                        str(command_string))))
     # The "tail" command below prevents a "egrep: write error: Broken pipe"
     # error if the user is piping the output to a sub-process.
     # Use "egrep -v" to get rid of editorial output from openbmctool.py.