selftests/powerpc: Fix the clean rule since recent changes

The clean rule is broken for the powerpc tests:

  make[1]: Entering directory 'tools/testing/selftests/powerpc'
  Makefile:63: warning: overriding recipe for target 'clean'
  ../lib.mk:51: warning: ignoring old recipe for target 'clean'
  /bin/sh: 3: Syntax error: end of file unexpected (expecting "done")
  Makefile:63: recipe for target 'clean' failed

Fixes: a8ba798b ("selftests: enable O and KBUILD_OUTPUT")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/powerpc/Makefile

@@ -62,7 +62,8 @@ endef
 clean:
 	@for TARGET in $(SUB_DIRS); do \
 		BUILD_TARGET=$$OUTPUT/$$TARGET;	\
-		$(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET clean;\ done;
+		$(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET clean; \
+	done;
 	rm -f tags
 
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