Fix linting warnings and add linting checks into the workflow. (#155)

diff --git a/.github/workflows/bazel_lint.yml b/.github/workflows/bazel_lint.yml
index 6556a92..754197e 100644
--- a/.github/workflows/bazel_lint.yml
+++ b/.github/workflows/bazel_lint.yml
@@ -36,5 +36,5 @@
       with:
         go-version: '^1.13.1' # The Go version to download (if necessary) and use.
     - run: go get github.com/bazelbuild/buildtools/buildifier
-    - run: buildifier -mode=check $(find . -type f \( -name BUILD.bazel -or -name BUILD -or -name *.bzl \))
+    - run: buildifier -lint=warn -mode=check $(find . -type f \( -name BUILD.bazel -or -name BUILD -or -name *.bzl \))
 
diff --git a/fuzzing/private/fuzz_test.bzl b/fuzzing/private/fuzz_test.bzl
index 36f922b..eb45465 100644
--- a/fuzzing/private/fuzz_test.bzl
+++ b/fuzzing/private/fuzz_test.bzl
@@ -216,6 +216,7 @@
 
     Args:
         name: A unique name for this target. Required.
+        srcs: A list of source files of the target.
         target_class: The class that contains the static fuzzerTestOneInput
           method. Defaults to the same class main_class would.
         transitive_native_deps: A list of all native libraries that the fuzz
diff --git a/fuzzing/private/java_utils.bzl b/fuzzing/private/java_utils.bzl
index 3b05cd9..a6005a4 100644
--- a/fuzzing/private/java_utils.bzl
+++ b/fuzzing/private/java_utils.bzl
@@ -14,17 +14,7 @@
 
 """Utilities and helper rules for Java fuzz tests."""
 
-load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
 load("//fuzzing/private:binary.bzl", "fuzzing_binary_transition")
-load(
-    "//fuzzing/private:instrum_opts.bzl",
-    "instrum_defaults",
-    "instrum_opts",
-)
-load(
-    "//fuzzing:instrum_opts.bzl",
-    "sanitizer_configs",
-)
 
 # A Starlark reimplementation of a part of Bazel's JavaCommon#determinePrimaryClass.
 def determine_primary_class(srcs, name):