wifi: mt76: fix potential memory leak in mt76_wmac_probe()

wifi: mt76: fix potential memory leak in mt76_wmac_probe()

In mt76_wmac_probe(), when the mt76_alloc_device() call succeeds, memory
is allocated for both struct ieee80211_hw and a workqueue. However, on
the error path, the workqueue is not freed. Fix that by calling
mt76_free_device() on the error path.

Fixes: c8846e101502 ("mt76: add driver for MT7603E and MT7628/7688")
Signed-off-by: Abdun Nihaal <abdun.nihaal@gmail.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://patch.msgid.link/20250709145532.41246-1-abdun.nihaal@gmail.com
Signed-off-by: Felix Fietkau <nbd@nbd.name>