net: dql: Avoid calling BUG() when WARN() is enough

net: dql: Avoid calling BUG() when WARN() is enough

If the dql_queued() function receives an invalid argument, WARN about it
and continue, instead of crashing the kernel.

This was raised by checkpatch, when I am refactoring this code (see
following patch/commit)

	WARNING: Do not crash the kernel unless it is absolutely unavoidable--use WARN_ON_ONCE() plus recovery code (if feasible) instead of BUG() or variants

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240411192241.2498631-2-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>