pylint: fix various errors caught by 3.2

In preparation for adding to CI run_tests, cleanup the current codebase.

Bug: None
Test: `./run_tests`
Change-Id: Ie1a07b644b6b3405cb347e2cc062818d0b6bdc51
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repohooks/+/556725
Reviewed-by: Raul Rangel <rrangel@google.com>
Tested-by: Mike Frysinger <vapier@google.com>
Commit-Queue: Mike Frysinger <vapier@google.com>

pre-upload.py

diff --git a/pre-upload.py b/pre-upload.py
index a51707c..7117cad 100755
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -442,6 +442,7 @@
             )
 
             def run_hooks(hooks):
+                # pylint: disable=cell-var-from-loop
                 futures = (
                     executor.submit(
                         _run_hook, hook, project, commit, desc, diff

rh/hooks.py

diff --git a/rh/hooks.py b/rh/hooks.py
index 1ba3b8b..4750183 100644
--- a/rh/hooks.py
+++ b/rh/hooks.py
@@ -1305,6 +1305,7 @@
 # Hooks that projects can opt into.
 # Note: Make sure to keep the top level README.md up to date when adding more!
 BUILTIN_HOOKS = {
+    # pylint: disable=line-too-long
     "aidl_format": check_aidl_format,
     "alint": check_alint,
     "android_test_mapping_format": check_android_test_mapping,

rh/utils.py

diff --git a/rh/utils.py b/rh/utils.py
index 0a599f3..f5aa041 100644
--- a/rh/utils.py
+++ b/rh/utils.py
@@ -358,11 +358,11 @@
 
     if isinstance(cmd, str):
         if not shell:
-            raise Exception("Cannot run a string command without a shell")
+            raise TypeError("Cannot run a string command without a shell")
         cmd = ["/bin/bash", "-c", cmd]
         shell = False
     elif shell:
-        raise Exception("Cannot run an array command with a shell")
+        raise TypeError("Cannot run an array command with a shell")
 
     # If we are using enter_chroot we need to use enterchroot pass env through
     # to the final command.

rh/utils_unittest.py

diff --git a/rh/utils_unittest.py b/rh/utils_unittest.py
index 5b977cd..9de9186 100755
--- a/rh/utils_unittest.py
+++ b/rh/utils_unittest.py
@@ -97,7 +97,7 @@
 
     def test_basic(self):
         """Basic test we can create a normal instance."""
-        rh.utils.CalledProcessError(0, ["mycmd"])
+        _ = rh.utils.CalledProcessError(0, ["mycmd"])
 
     def test_stringify(self):
         """Check stringify() handling."""