Don't list images for other arches as 'missing'

...But also be careful not to treat them as 'unknown' either.
This avoids the ansible plays regenerating outdated images (we
try to avoid that and just have the cron job do it).

createhdds.py

@@ -60,8 +60,8 @@ def supported_arches():
     """Provides a list of the arches for which virt-install images can
     be built on this host.
     """
-    powerpc_arches = ['ppc64', 'ppc64le']
-    intel_arches = ['i686', 'x86_64']
+    powerpc_arches = ['ppc64', 'ppc64le', 'noarch']
+    intel_arches = ['i686', 'x86_64', 'noarch']
     if CPUARCH in powerpc_arches:
         supported_arches = powerpc_arches
     elif CPUARCH in intel_arches:
@@ -93,6 +93,7 @@ class GuestfsImage(object):
     def __init__(self, name, size, imgver='', filesystem='ext4', label='mbr', parts=None,
                  writes=None, uploads=None, name_extras=None):
         self.name = name
+        self.arch = 'noarch'
         self.size = handle_size(size)
         # guestfs images are never outdated
         self.outdated = False
@@ -568,7 +569,7 @@ def check(hdds, nextrel=None):
 
     # Now determine if images are absent or outdated
     for img in expected:
-        if not os.path.isfile(img.filename):
+        if img.arch in supported_arches() and not os.path.isfile(img.filename):
             missing.append(img)
             continue
         if img.outdated: