wifi: mt76: mt7996: remove redundant pdev->bus check in probe

wifi: mt76: mt7996: remove redundant pdev->bus check in probe

Drop the unnecessary pdev->bus NULL check in mt7996_pci_probe() since
the pointer is already dereferenced earlier in mt76_pci_disable_aspm(),
making the check dead code. Silences the related Smatch warning.

Fixes: 377aa17d2aed ("wifi: mt76: mt7996: Add NPU offload support to MT7996 driver")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260522-mt7996-pdev-bus-fix-v1-1-c91716484365@kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>