Use method delete_if_exists from oslo.utils

oslo.utils provides same method[1] in module fileutils,
and just use it.

TrivialFix

[1]9981276fe6/oslo_utils/fileutils.py (L49-L60)

Change-Id: Ic83cfa28f96f97af17f19eda950fc6709ce12760

ironic/common/utils.py

@@ -135,18 +135,6 @@ def random_alnum(size=32):
     return ''.join(random.choice(characters) for _ in range(size))
 
 
-def delete_if_exists(pathname):
-    """delete a file, but ignore file not found error."""
-
-    try:
-        os.unlink(pathname)
-    except OSError as e:
-        if e.errno == errno.ENOENT:
-            return
-        else:
-            raise
-
-
 def is_valid_boolstr(val):
     """Check if the provided string is a valid bool string or not."""
     boolstrs = ('true', 'false', 'yes', 'no', 'y', 'n', '1', '0')

ironic/drivers/modules/console_utils.py

@@ -29,11 +29,11 @@ import time
 from ironic_lib import utils as ironic_utils
 from oslo_log import log as logging
 from oslo_service import loopingcall
+from oslo_utils import fileutils
 from oslo_utils import netutils
 
 from ironic.common import exception
 from ironic.common.i18n import _, _LE, _LW
-from ironic.common import utils
 from ironic.conf import CONF
 
 
@@ -117,13 +117,13 @@ def make_persistent_password_file(path, password):
     """Writes a file containing a password until deleted."""
 
     try:
-        utils.delete_if_exists(path)
+        fileutils.delete_if_exists(path)
         with open(path, 'wb') as file:
             os.chmod(path, 0o600)
             file.write(password.encode())
         return path
     except Exception as e:
-        utils.delete_if_exists(path)
+        fileutils.delete_if_exists(path)
         raise exception.PasswordFileFailedToCreate(error=e)