selftests: fix clean target in kcmp Makefile

Signed-off-by: NRamkumar Ramachandra <artagnon@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

tools/testing/selftests/kcmp/Makefile

@@ -25,5 +25,4 @@ run_tests: all
 	@./kcmp_test || echo "kcmp_test: [FAIL]"
 
 clean:
-	rm -fr ./run_test
-	rm -fr ./test-file
+	$(RM) kcmp_test kcmp-test-file