fix clang format installation

templates/tools/dockerfile/clang_format.include

@@ -1,6 +1,5 @@
 RUN apt-get update && apt-get -y install wget xz-utils
 RUN wget http://releases.llvm.org/5.0.0/clang+llvm-5.0.0-linux-x86_64-ubuntu14.04.tar.xz
 RUN tar xf clang+llvm-5.0.0-linux-x86_64-ubuntu14.04.tar.xz
-ENV PATH=clang+llvm-5.0.0-linux-x86_64-ubuntu14.04/bin:$PATH
+RUN ln -s /clang+llvm-5.0.0-linux-x86_64-ubuntu14.04/bin/clang-format /usr/local/bin/clang-format
 ENV CLANG_FORMAT=clang-format
-

tools/dockerfile/grpc_clang_format/Dockerfile

@@ -17,9 +17,8 @@ FROM debian:jessie
 RUN apt-get update && apt-get -y install wget xz-utils
 RUN wget http://releases.llvm.org/5.0.0/clang+llvm-5.0.0-linux-x86_64-ubuntu14.04.tar.xz
 RUN tar xf clang+llvm-5.0.0-linux-x86_64-ubuntu14.04.tar.xz
-ENV PATH=clang+llvm-5.0.0-linux-x86_64-ubuntu14.04/bin:$PATH
+RUN ln -s /clang+llvm-5.0.0-linux-x86_64-ubuntu14.04/bin/clang-format /usr/local/bin/clang-format
 ENV CLANG_FORMAT=clang-format
 
-
 ADD clang_format_all_the_things.sh /
 CMD ["echo 'Run with tools/distrib/clang_format_code.sh'"]

tools/dockerfile/test/sanity/Dockerfile

@@ -103,10 +103,9 @@ RUN ./bazel-0.4.4-installer-linux-x86_64.sh
 RUN apt-get update && apt-get -y install wget xz-utils
 RUN wget http://releases.llvm.org/5.0.0/clang+llvm-5.0.0-linux-x86_64-ubuntu14.04.tar.xz
 RUN tar xf clang+llvm-5.0.0-linux-x86_64-ubuntu14.04.tar.xz
-ENV PATH=clang+llvm-5.0.0-linux-x86_64-ubuntu14.04/bin:$PATH
+RUN ln -s /clang+llvm-5.0.0-linux-x86_64-ubuntu14.04/bin/clang-format /usr/local/bin/clang-format
 ENV CLANG_FORMAT=clang-format
 
-
 # Prepare ccache
 RUN ln -s /usr/bin/ccache /usr/local/bin/gcc
 RUN ln -s /usr/bin/ccache /usr/local/bin/g++