[BUGFIX PATCH] tools: Let O= makes handle a relative path with -C option

[Masami Hiramatsu <mhiramat@kernel.org>]

When I compiled tools/bootconfig from top directory with
-C option, the O= option didn't work correctly if I passed
a relative path.

  $ make O=./builddir/ -C tools/bootconfig/
  make: Entering directory '/home/mhiramat/ksrc/linux/tools/bootconfig'
  ../scripts/Makefile.include:4: *** O=./builddir/ does not exist.  Stop.
  make: Leaving directory '/home/mhiramat/ksrc/linux/tools/bootconfig'

The O= directory existence check failed because the check
script ran in the build target directory instead of the
directory where I ran the make command.

To fix that, once change directory to $(PWD) and check O=
directory, since the PWD is set to where the make command
runs.

Fixes: c883122acc0d ("perf tools: Let O= makes handle relative paths")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 tools/scripts/Makefile.include |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index ded7a950dc40..6d2f3a1b2249 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -1,8 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 ifneq ($(O),)
 ifeq ($(origin O), command line)
-	dummy := $(if $(shell test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
-	ABSOLUTE_O := $(shell cd $(O) ; pwd)
+	dummy := $(if $(shell cd $(PWD); test -d $(O) || echo $(O)),$(error O=$(O) does not exist),)
+	ABSOLUTE_O := $(shell cd $(PWD); cd $(O) ; pwd)
 	OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
 	COMMAND_O := O=$(ABSOLUTE_O)
 ifeq ($(objtree),)