tests/qtest/cxl-test: Clean up temporary directories after testing

It's good style to clean up temporary directories when they
are not needed anymore.

Message-Id: <20230622114132.372898-1-thuth@redhat.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
diff --git a/tests/qtest/cxl-test.c b/tests/qtest/cxl-test.c
index edcad4a..a600331 100644
--- a/tests/qtest/cxl-test.c
+++ b/tests/qtest/cxl-test.c
@@ -124,6 +124,7 @@
 
     qtest_start(cmdline->str);
     qtest_end();
+    rmdir(tmpfs);
 }
 
 static void cxl_t3d_persistent(void)
@@ -138,6 +139,7 @@
 
     qtest_start(cmdline->str);
     qtest_end();
+    rmdir(tmpfs);
 }
 
 static void cxl_t3d_volatile(void)