Fix crash where MTU allowed to be set too large
Fix crash where MTU allowed to be set too large

As previously written, a remote device could request, and we would
accept an MTU larger than what we could support.

ComputeCycles/bluez,silent-snowman/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,ComputeCycles/bluez,ComputeCycles/bluez,mapfau/bluez,silent-snowman/bluez,silent-snowman/bluez,pkarasev3/bluez,silent-snowman/bluez,pkarasev3/bluez,pkarasev3/bluez,ComputeCycles/bluez