[CI] Specify style for clang-format explicitly

When the "-style" option is not specified, clang-format looks for ".clang-format".
Since we don't have this file in the project, the tool finds it recursively in parent directories.
If occasionally there is a .clang-format of some other project, it will be chosen.

Author: tkrasnukha

ci/clang-format.sh

@@ -3,5 +3,5 @@
 set -e
 
 echo "Checking clang-format"
-find -name *.h -or -name *.cpp | xargs clang-format -i
+find -name *.h -or -name *.cpp | xargs clang-format -i -style=llvm
 git diff --exit-code