In lock_iovec() if lock_user() failed we were doing an unlock_user
but not a free(vec), which is the wrong way round. We were also
assuming that free() and unlock_user() don't touch errno, which
is not guaranteed. Fix both these problems.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>