[PATCH] perf: python: Fix build when PYTHON_CONFIG is user supplied

[James Clark]

The previous change to Python autodetection had a small mistake where
the auto value was used to determine the Python binary, rather than the
user supplied value. The Python binary is only used for one part of the
build process, rather than the final linking, so it was producing
correct builds in most scenarios, especially when the auto detected
value matched what the user wanted, or the system only had a valid set
of Pythons.

Change it so that the Python binary path is derived from either the
PYTHON_CONFIG value or PYTHON value, depending on what is specified by
the user. This was the original intention.

This error was spotted in a build failure an odd cross compilation
environment after commit 4c41cb46a732fe82 ("perf python: Prefer
python3") was merged.

Fixes: 630af16eee495f58 ("perf tools: Use Python devtools for version autodetection rather than runtime")
Signed-off-by: James Clark <james.clark@xxxxxxx>
---
 tools/perf/Makefile.config | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index d3c254c0f5c6..a69da9f34486 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -265,7 +265,7 @@ endif
 # defined. get-executable-or-default fails with an error if the first argument is supplied but
 # doesn't exist.
 override PYTHON_CONFIG := $(call get-executable-or-default,PYTHON_CONFIG,$(PYTHON_AUTO))
-override PYTHON := $(call get-executable-or-default,PYTHON,$(subst -config,,$(PYTHON_AUTO)))
+override PYTHON := $(call get-executable-or-default,PYTHON,$(subst -config,,$(PYTHON_CONFIG)))
 
 grep-libs  = $(filter -l%,$(1))
 strip-libs  = $(filter-out -l%,$(1))
-- 
2.28.0