Store SOL character data input length separately than the data length

of the whole packet.  Turns out we need it in order to determine whether
the BMC only accepted part of our data.

ipmitool/include/ipmitool/ipmi.h

@@ -111,6 +111,7 @@ struct ipmi_v2_payload {
 
 		struct {
 			unsigned char data[BUF_SIZE];
+			unsigned short character_count;
 			unsigned char packet_sequence_number;
 			unsigned char acked_packet_number;
 			unsigned char accepted_character_count;