perf build: Pass O option to Makefile.perf in build-test

Unlike tools/perf/Makefile, tools/perf/Makefile.perf obey 'O' option
when it is passed through cmdline only, due to code in
tools/scripts/Makefile.include:

 ifneq ($(O),)
 ifeq ($(origin O), command line)
 	...
 	ABSOLUTE_O := $(shell cd $(O) ; pwd)
 	OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
 endif
 endif

This patch passes 'O' to Makefile.perf through cmdline explicitly
to make it follow O variable during build-test.

'make clean' should have identical 'O' option with 'make'. If not,
config-clean may error.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452830421-77757-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/make

@@ -5,7 +5,7 @@ ifeq ($(MAKECMDGOALS),)
 # no target specified, trigger the whole suite
 all:
 	@echo "Testing Makefile";      $(MAKE) -sf tests/make MK=Makefile
-	@echo "Testing Makefile.perf"; $(MAKE) -sf tests/make MK=Makefile.perf SET_PARALLEL=1
+	@echo "Testing Makefile.perf"; $(MAKE) -sf tests/make MK=Makefile.perf SET_PARALLEL=1 SET_O=1
 else
 # run only specific test over 'Makefile'
 %:
@@ -13,6 +13,14 @@ else
 endif
 else
 PERF := .
+O_OPT :=
+
+ifneq ($(O),)
+  FULL_O := $(shell readlink -f $(O) || echo $(O))
+  ifeq ($(SET_O),1)
+    O_OPT := 'O=$(FULL_O)'
+  endif
+endif
 
 PARALLEL_OPT=
 ifeq ($(SET_PARALLEL),1)
@@ -256,12 +264,12 @@ endif
 
 MAKEFLAGS := --no-print-directory
 
-clean := @(cd $(PERF); make -s -f $(MK) clean >/dev/null)
+clean := @(cd $(PERF); make -s -f $(MK) $(O_OPT) clean >/dev/null)
 
 $(run):
 	$(call clean)
 	@TMP_DEST=$$(mktemp -d); \
-	cmd="cd $(PERF) && make -f $(MK) $(PARALLEL_OPT) DESTDIR=$$TMP_DEST $($@)"; \
+	cmd="cd $(PERF) && make -f $(MK) $(PARALLEL_OPT) $(O_OPT) DESTDIR=$$TMP_DEST $($@)"; \
 	echo "- $@: $$cmd" && echo $$cmd > $@ && \
 	( eval $$cmd ) >> $@ 2>&1; \
 	echo "  test: $(call test,$@)" >> $@ 2>&1; \