[ModemManager] [PATCH] Fix two bugs with multipart SMS handling: signals and listing.

[Nathan Williams <njw google com>]

These errors slipped through my testing last time.

(For ChromeOS development, I have rigged up a black-box ModemManager
test system under autotest, which creates a fake gudev device and a
fake modem that responds to AT commands to test this kind of thing. It
might be interesting to adapt it into the MM build system somehow;
right now it's part of our big autotest suite. The tests are here:

http://git.chromium.org/gitweb/?p=chromiumos/third_party/autotest.git;a=tree;f=client/site_tests/network_ModemManagerSMS
http://git.chromium.org/gitweb/?p=chromiumos/third_party/autotest.git;a=tree;f=client/site_tests/network_ModemManagerSMSSignal

and use the tools I wrote here:

http://git.chromium.org/gitweb/?p=chromiumos/third_party/autotest.git;a=tree;f=client/deps/fakegudev
http://git.chromium.org/gitweb/?p=chromiumos/third_party/autotest.git;a=tree;f=client/deps/fakemodem
)

    - Nathan