Bluetooth: Controller: ISO: Setting CONFIG_BT_CTLR_ISO_TX_BUFFERS=4 breaks non-ISO data

[Thalley]

Describe the bug
If CONFIG_BT_CTLR_ISO_TX_BUFFERS=4 and CONFIG_BT_CTLR_ADV_ISO=y then non-ISO TX buffer overflow occurs (e.g. when doing GATT operations). It also fails for larger values than 4.

To Reproduce
Run e.g. tests/bluetooth/bsim_bt/bsim_test_audio/test_scripts/vcs.sh with CONFIG_BT_CTLR_ISO_TX_BUFFERS=4 (instead of the CONFIG_BT_CTLR_ISO_TX_BUFFERS=3 which is the default/current at the time of this issue) with #46204.

Expected behavior
That the test passes with CONFIG_BT_CTLR_ISO_TX_BUFFERS=4 as it does with CONFIG_BT_CTLR_ISO_TX_BUFFERS=3.

Impact
Minor

Logs and console output
Running the test will result in the following:

d_01: @00:00:00.835740  [00:00:00.835,723] <dbg> bt_vcs_client: vcs_discover_func: Setup complete for VCS
d_00: @00:00:01.086560  [00:00:01.086,547] <err> bt_ctlr_hci: Tx Buffer Overflow
d_00: @00:00:01.086560  [00:00:01.086,547] <wrn> bt_hci_core: Data buffer overflow (link type 0x01)
d_00: @00:00:01.086560  [00:00:01.086,547] <err> bt_conn: Unable to send to driver (err -105)
d_01: @00:00:30.000000 ERROR: (WEST_TOPDIR/zephyr/tests/bluetooth/bsim_bt/bsim_test_audio/src/common.c:73): test failed (not passed after 30 seconds)

Environment (please complete the following information):

• Commit SHA or Version used: LE Audio: Broadcast audio test update #46204

Additional contextN/A

[cvinayak]

if CONFIG_BT_ISO=y then the wrong bt_dev.le.iso_pkts will be returned for ACL packet transmission, right?

[Thalley]

if CONFIG_BT_ISO=y then the wrong bt_dev.le.iso_pkts will be returned for ACL packet transmission, right?

It would appear so due to the || instead of a &&