update_kernel_afdo: Add kernel 5.10

Add 5.10 and skip the kernel AFDO update if the channel does not support
AFDO.
Force worktree clean-up if the update fails.

BUG=b:218702582
TEST=./afdo_tools/update_kernel_afdo main

Change-Id: I9282e7cf600c27ba5a8b7e7329eae1512804af29
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/3508821
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Tested-by: Denis Nikitin <denik@chromium.org>
Commit-Queue: Denis Nikitin <denik@chromium.org>
1 file changed