Apply patch so that slapos.cookbook can work both in linux and cygwin

slapos/recipe/librecipe/execute.py

@@ -43,6 +43,7 @@ def _wait_files_creation(file_list):
             directories[dirname][event.name] = True
 
   finally:
+    if isinstance(fd, int):
       os.close(fd)
 
 def execute(args):

slapos/recipe/librecipe/inotify.py

@@ -48,4 +48,5 @@ def subfiles(directory):
       subfiles = [file_.name for file_ in inotifyx.get_events(watchfd)]
 
   finally:
+    if isinstance(watchfd, int): 
       os.close(watchfd)

slapos/recipe/lockfile.py

@@ -57,6 +57,7 @@ class LockFile(object):
     except IOError: # add_watch failed
       pass
     finally:
+        if isinstance(inotify_fd, int):
           os.close(inotify_fd)
 
     self.__enter__()