[rilmodem] Minor phonebook code cleanup

Signed-off-by: Tommi Kenakkala <tommi.kenakkala@oss.tieto.com>
[rilmodem] Updated devinfo comments

Signed-off-by: Tommi Kenakkala <tommi.kenakkala@oss.tieto.com>
Merge pull request #245 from tkenakka/master

Minor code cleanup
[rilmodem] Mem leak fixes to sms sending and receiving

Signed-off-by: Tommi Kenakkala <tommi.kenakkala@oss.tieto.com>
Merge pull request #246 from tkenakka/leaksms

[rilmodem] Mem leak fixes to sms sending and receiving
[rilmodem] Fix stk mem leaks
[rilmodem] Fix ussd mem leaks

Signed-off-by: Tommi Kenakkala <tommi.kenakkala@oss.tieto.com>
[rilmodem] Fix supplementary service mem leak

Signed-off-by: Tommi Kenakkala <tommi.kenakkala@oss.tieto.com>