[PATCH] perf: fix compile error when rebuilding

["Changqing Li" <changqing.li@windriver.com>]

From: Changqing Li <changqing.li@windriver.com>

Fix error like:
Makefile.perf:597: recipe for target
'intel_x86_64-wrs-linux/perf/1.0-r9/perf-1.0/perf-in.o] Error 2
Makefile.perf:220: recipe for target 'sub-make' failed
make[1]: *** [sub-make] Error 2
Makefile:69: recipe for target 'all' failed
make: *** [all] Error 2

during rebuilding, when kernel version changed, some
source files also maybe changed. It could happened
that the source under ${S} messed up with some already
dropped files and also new files. Fix by clean the ${S}
before copy source files.

Signed-off-by: Changqing Li <changqing.li@windriver.com>
---
 meta/recipes-kernel/perf/perf.bb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/meta/recipes-kernel/perf/perf.bb b/meta/recipes-kernel/perf/perf.bb
index e005eb0..c4b7b77 100644
--- a/meta/recipes-kernel/perf/perf.bb
+++ b/meta/recipes-kernel/perf/perf.bb
@@ -147,6 +147,7 @@ python copy_perf_source_from_kernel() {
     src_dir = d.getVar("STAGING_KERNEL_DIR")
     dest_dir = d.getVar("S")
     bb.utils.mkdirhier(dest_dir)
+    bb.utils.prunedir(dest_dir)
     for s in sources:
         src = oe.path.join(src_dir, s)
         dest = oe.path.join(dest_dir, s)
-- 
2.7.4