classes/lib: Fix getcmdstatus breakage

I mistakenly thought subprocess had getcmdstatus in python 2. It doesn't so lets
add a wrapper and have this work in both worlds.

(From OE-Core rev: 2253e9f12734c6e6aa489942b5e4628eca1fa29d)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/utils.py

@@ -1,3 +1,10 @@
+try:
+    # Python 2
+    import commands as cmdstatus
+except ImportError:
+    # Python 3
+    import subprocess as cmdstatus
+
 def read_file(filename):
     try:
         f = file( filename, "r" )
@@ -123,3 +130,6 @@ def packages_filter_out_system(d):
         if pkg not in blacklist and localepkg not in pkg:
             pkgs.append(pkg)
     return pkgs
+
+def getstatusoutput(cmd):
+    return cmdstatus.getstatusoutput(cmd)