perf tools: Fix building error for arm64.

Commit b11db658 ("perf tools: Fix build
error on ARCH=i386/x86_64/sparc64") uses sed on ARCH, which triggers a
bug in sequence of sed expression, where 's/arm.*/arm/' will replace
'arm64' to 'arm', causes arm64 building failure.

This patch prevent 'arm64' to be mached for 'arm.*' case.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1426598987-75245-1-git-send-email-wangnan0@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/config/Makefile.arch

@@ -4,7 +4,7 @@ endif
 
 ARCH := $(shell echo $(ARCH) | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
                                   -e s/sun4u/sparc/ -e s/sparc64/sparc/ \
-                                  -e s/arm.*/arm/ -e s/sa110/arm/ \
+                                  -e /arm64/!s/arm.*/arm/ -e s/sa110/arm/ \
                                   -e s/s390x/s390/ -e s/parisc64/parisc/ \
                                   -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
                                   -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ \