remove version check for clang-format,test=document_fix (#5004)

.travis/codestyle/clang_format.hook

 #!/bin/bash
 set -e
 
-readonly VERSION="3.8"
-
-version=$(clang-format -version)
-
-if ! [[ $version == *"$VERSION"* ]]; then
-    echo "clang-format version check failed."
-    echo "a version contains '$VERSION' is needed, but get '$version'"
-    echo "you can install the right version, and make an soft-link to '\$PATH' env"
-    exit -1
-fi
-
 clang-format $@