Correction of encoder printouts

There are a few encoder print-outs that are not correct.

Thus corrections are proposed to

• print out a message and exit the encoder when the channel-aware mode is requested in IVAS
• fix the VBR option exit
• properly return an error for function IVAS_ENC_PrintConfig()
• fix printout for audio bandwidth limitation
• fix error bitrate printout in VBR mode when requested in IVAS