By inspection, tinfoil handles two of the three command exit cases but
one is missing. Add the CommandExit case in case this is the cause of
one of our recipetool/devtool hangs. Regardless, the fix is necessary.
(Bitbake rev: eadddd94835b6b6a8517dfed3d29e6dbb2d35988)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>