tests: Avoid leak of va_list

Add a va_end() call to pair with our va_start().

Bug: 168890623
Test: TreeHugger

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
Change-Id: I23455e463067b84552daea6c5c2b63d5ddb8cd5f
1 file changed