Handle root inflammation event properly.

Root inflammation event is a BQR event, not a BQR link quality event.

Currently, handle_root_inflammation function in hci_layer.cc is
unreachable because we try to check is the BQR link quality event is
valid. It will not be valid because root inflammation event is a BQR
event but not a BQR link quality event.

Bug: 248063430
Bug: 245578454
Bug: 243824983
Tag: #gd-refactor
Test: atest bluetooth_test_gd_unit

Change-Id: I934918605335e3d12cff14eedd0cea96a9e01df5