He Kuang reported that current perf tools failed to build when ARCH
variable was given like above.

It was because the name is different that internal directory name.  I
can see that David's sparc64 build has same problem.

So fix it by applying the sed conversion script to the command line ARCH
variable also, and fixing the converted name there (i.e. i386/x86_64 ->
x86, sparc64 -> sparc).
Reported-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: He Kuang <hekuang@huawei.com>
Acked: Jiri Olsa <jolsa@redhat.com>
Cc: David Ahern <david.ahern@oracle.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1425270663-10215-1-git-send-email-namhyung@kernel.org
[ Resolved conflict with 4861f87c "Make sparc64 arch point to sparc" ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>