narrowed down exception we ignore and fail if any other unexpected one

crops up.
Signed-off-by: Brian Coca <briancoca+dev@gmail.com>

library/system/setup

@@ -626,28 +626,27 @@ class LinuxHardware(Hardware):
             if line.startswith('/'):
                 fields = line.rstrip('\n').split()
                 if(fields[2] != 'none'):
+                    size_total = None
+                    size_available = None
                     try:
                         statvfs_result = os.statvfs(fields[1])
-                        self.facts['mounts'].append(
-                            {'mount': fields[1],
-                             'device':fields[0],
-                             'fstype': fields[2],
-                             'options': fields[3],
-                             # statvfs data
-                             'size_total': statvfs_result.f_bsize * statvfs_result.f_blocks,
-                             'size_available': statvfs_result.f_bsize * (statvfs_result.f_bavail),
-                             })
+                        size_total = statvfs_result.f_bsize * statvfs_result.f_blocks
+                        size_available = statvfs_result.f_bsize * (statvfs_result.f_bavail)
                     except OSError, e:
-                        # don't have access to stat so we'll set to None
-                        self.facts['mounts'].append(
-                            {'mount': fields[1],
-                             'device':fields[0],
-                             'fstype': fields[2],
-                             'options': fields[3],
-                             # statvfs data
-                             'size_total': None,
-                             'size_available': None,
-                             })
+                        if e.errno == errno.ENOENT:
+                            pass
+                        else:
+                            self.fail_json(msg=e.strerror)
+
+                    self.facts['mounts'].append(
+                        {'mount': fields[1],
+                         'device':fields[0],
+                         'fstype': fields[2],
+                         'options': fields[3],
+                         # statvfs data
+                         'size_total': size_total,
+                         'size_available': size_available,
+                         })
 
     def get_device_facts(self):
         self.facts['devices'] = {}