kernel: Bluetooth: MGMT: Fix possible crash on mgmt_index_removed

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: Fix possible crash on mgmtindexremoved If mgmtindexremoved is called while there are commands queued on cmdsync it could lead to crashes like the bellow trace: 0x0000053D: listdelentryvalidorreport+0x98/0xdc...