kunit: Fix memory leak in test_stream_append

get_string() returns a new allocated string which needs to be freed after use.

Signed-off-by: Sagi Shahar <sagis@google.com>
Change-Id: I0df8b379445a077500aa4ec9a6177ea440a0925d

test/test-stream.c

diff --git a/test/test-stream.c b/test/test-stream.c
index f9869ad..43f28c4 100644
--- a/test/test-stream.c
+++ b/test/test-stream.c
@@ -44,6 +44,7 @@ static void test_stream_append(struct test_stream *this,
 	}
 
 	this->add(this, other_content);
+	kfree(other_content);
 }
 
 static void test_stream_clear(struct test_stream *this)