Bump git hooks version to 6d91964

Bug: chromium:1430956,chromium:543704
Change-Id: Iff268ae2fb8fd11f3e1baf87ee27f48b81f16577
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/71488
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@google.com>
Tested-by: Shahbaz Youssefi <syoussefi@google.com>
diff --git a/third_party/git-hooks b/third_party/git-hooks
index de5ff14..6d91964 160000
--- a/third_party/git-hooks
+++ b/third_party/git-hooks
@@ -1 +1 @@
-Subproject commit de5ff141c9c35e3999a19379cd68c80031a74e46
+Subproject commit 6d91964d33adee28dda9c7faf9ffd6f4672c381c