llvm_tools: rename update_chromeos_llvm_next_hash.py

Now that update_chromeos_llvm_next_hash.py can be used to create LLVM
roll CLs too, rename it to update_chromeos_llvm_hash.py to avoid
confusion.

BUG=chromium:1041590

TEST=local tests

Change-Id: I18df7c2fe1f73566d053e963e606d28562637c6b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2119808
Tested-by: Jian Cai <jiancai@google.com>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
5 files changed