docker/docker — pull request #8850 by shuai-z (2014-10-30 05:53:03+00:00)
Title: Clear the internal state before raising error.

If we need to raise an error, make sure the internal state is clean, because
a successful driver.Get() may have its internal state changed (eg. counting,
or mounts), while callers will only do that after a succussful Mount().

Signed-off-by: shuai-z