[CAL] Use 0xFF instead of 0xFFFFFFFF for dialing context
To fix:

D/RILJ    (  689): [3814]> DIAL
D/use-Rlog/RLOG-RIL-Mocha-SND(  123): ril_request_set_mute - mute data is 0
E/use-Rlog/RLOG-RIL-Mocha-CALL(  123): Call context with Id -1 not found!
........
E/use-Rlog/RLOG-RIL-Mocha-CALL(  123): ipc_call_error: test me!(callNo:255, error:1)
E/use-Rlog/RLOG-RIL-Mocha-CALL(  123): Call context with Id 255 not found!
D/use-Rlog/RLOG-RIL-Mocha-UTIL(  123): [0000]   FF 00 00 00 01 00 00 00
[CALL] fixed ril_request_switch_waiting_or_holding_and_active
[CALL] Fix ipc_call_hold
[CALL] fix code style
[SMS] Small fix