CHERRY-PICK: get_version: revise GetFirmwareVersions regular expression

The number of space characters in version line from
chromeos-firmwareupdate might be zero, so change '\s+' to '\s*'.

BUG=none
TEST=manually

Change-Id: I20bb2b898af1a3d326f8b4f03eaa97b2b025e2e9
Reviewed-on: https://chromium-review.googlesource.com/564979
Reviewed-by: Youcheng Syu <youcheng@chromium.org>
Commit-Queue: Jesper Lin <jesper_lin@wistron.corp-partner.google.com>
Tested-by: Jesper Lin <jesper_lin@wistron.corp-partner.google.com>
diff --git a/py/tools/get_version.py b/py/tools/get_version.py
index 3910748..287b1d3 100644
--- a/py/tools/get_version.py
+++ b/py/tools/get_version.py
@@ -61,7 +61,7 @@
 
   versions = []
   for label in FIRMWARE_LABELS:
-    match = re.search('^' + label + ' version:\s+(.+)$', stdout, re.MULTILINE)
+    match = re.search('^' + label + r' version:\s*(.+)$', stdout, re.MULTILINE)
     versions.append(match.group(1) if match else None)
   return tuple(versions)