clang-format: use IndentGotoLabels to get rid of goto label indentation
This is done to follow 'Linux kernel coding style', same change was
added to .clang-format in linux kernel source recently:
https://github.com/torvalds/linux/commit/d7f6604341c74
We don't change it in current code base but let's follow it in all
future uses.
Signed-off-by: Pavel Tikhomirov <[email protected]>