minor tidy-ups & unused import rockstor#2564

Includes prior TODO re ascii to utf-8 on SMART
custom options.

src/rockstor/settings.py

@@ -19,7 +19,7 @@
 
 # Django settings for Rockstor project.
 import os
-import subprocess, distro
+import distro
 from huey import SqliteHuey
 
 DEBUG = False

src/rockstor/system/smart.py

@@ -97,7 +97,7 @@ def extended_info(device, custom_options="", test_mode=TESTMODE):
     Attribute name.
 
     :param device: disk device name
-    :param testmode: Not True causes cat from file rather than smartctl command
+    :param test_mode: Not True causes cat from file rather than smartctl command
     :return: dictionary of smart attributes extracted from device or test file
 
     """
@@ -440,9 +440,7 @@ def get_dev_options(dev_byid, custom_options=""):
         dev_options = [get_device_path(get_base_device_byid(dev_byid, TESTMODE))]
     else:
         # Convert string of custom options into a list ready for run_command
-        # TODO: think this ascii should be utf-8 as that's kernel standard
-        # TODO: or just use str(custom_options).split()
-        dev_options = custom_options.encode("ascii").split()
+        dev_options = custom_options.encode("utf-8").split()
         # Remove Rockstor native 'autodev' custom smart option raid dev target.
         # As we automatically add the full path by-id if a raid controller
         # target dev is not found, we can simply remove this option.

src/rockstor/system/users.py

@@ -75,8 +75,6 @@ def get_users(max_wait=60):
         timeout=max_wait,
     )
     out = result.stdout
-    err = result.stderr
-    rc = result.returncode
     # TODO: Report & handle exception reported via CompletedProcess (result)
     out_list = out.split("\n")
     # out_list looks like;
@@ -204,7 +202,7 @@ def smbpasswd(username, passwd):
     rc = p.returncode
     if rc != 0:
         raise CommandException(cmd, out, err, rc)
-    return (out, err, rc)
+    return out, err, rc
 
 
 def update_shell(username, shell):
@@ -235,7 +233,7 @@ def useradd(username, shell, uid=None, gid=None):
                 "User({0}) already exists, but her shell({1}) is "
                 "different from the input({2}).".format(username, pw_entry.shell, shell)
             )
-        return ([""], [""], 0)
+        return [""], [""], 0
 
     cmd = [USERADD, "-s", shell, "-m", username]
     if uid is not None: