[PATCH] tools/dma: fix building with O=

[Sasha Levin]

With O= set, "all" depends on $(OUTPUT)dma_map_benchmark, but the only
rule builds dma_map_benchmark in the source directory, and built-in
rules are disabled:

  make: *** No rule to make target '<O>/dma_map_benchmark', needed by 'all'.  Stop.

Build $(OUTPUT)dma_map_benchmark.

Fixes: f74ee32963f1b ("tools/dma: move dma_map_benchmark from selftests to tools/dma")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: LLM
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 tools/dma/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/dma/Makefile b/tools/dma/Makefile
index e4abf37bf020c..0c239a6b9eae5 100644
--- a/tools/dma/Makefile
+++ b/tools/dma/Makefile
@@ -38,8 +38,8 @@ prepare: $(OUTPUT)include/linux/map_benchmark.h
 FORCE:
 
 DMA_MAP_BENCHMARK = dma_map_benchmark
-$(DMA_MAP_BENCHMARK): prepare FORCE
-	$(CC) $(CFLAGS) $(DMA_MAP_BENCHMARK).c -o $(DMA_MAP_BENCHMARK)
+$(OUTPUT)$(DMA_MAP_BENCHMARK): prepare FORCE
+	$(CC) $(CFLAGS) $(DMA_MAP_BENCHMARK).c -o $@
 
 clean:
 	rm -f $(ALL_PROGRAMS)
-- 
2.53.0