Fix cppcheck with ccache

.travis/install.cppcheck

@@ -16,8 +16,13 @@ else
   version=$(git tag | tail -n 1)
 fi
 
+# pick native architecture
+native="$($CC -march=native -Q --help=target | grep march= | awk '{print $2}')"
+# this is required so that when running the job on a different architecture ccache understand
+# the object file should not be recycled
+
 git checkout $version
-make -j 4 install CFGDIR="$HOME/opt/share/cppcheck/" CXXFLAGS="-O2 -march=native -mtune=native -Wunreachable-code" PREFIX="$HOME/opt"
+make -j 4 install CFGDIR="$HOME/opt/share/cppcheck/" CXXFLAGS="-O2 -march="$native" -mtune="$native" -Wunreachable-code" PREFIX="$HOME/opt"
 cd ../
 
 cppcheck --version