octeon_ep: initialize mbox mutexes

The two mbox-related mutexes are destroyed in octep_ctrl_mbox_uninit(),
but the corresponding mutex_init calls were missing.
A "DEBUG_LOCKS_WARN_ON(lock->magic != lock)" warning was emitted with
CONFIG_DEBUG_MUTEXES on.

Initialize the two mutexes in octep_ctrl_mbox_init().

Fixes: 577f0d1b ("octeon_ep: add separate mailbox command and response queues")
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230729151516.24153-1-mschmidt@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/marvell/octeon_ep/octep_ctrl_mbox.c

@@ -98,6 +98,9 @@ int octep_ctrl_mbox_init(struct octep_ctrl_mbox *mbox)
 	writeq(OCTEP_CTRL_MBOX_STATUS_INIT,
 	       OCTEP_CTRL_MBOX_INFO_HOST_STATUS(mbox->barmem));
 
+	mutex_init(&mbox->h2fq_lock);
+	mutex_init(&mbox->f2hq_lock);
+
 	mbox->h2fq.sz = readl(OCTEP_CTRL_MBOX_H2FQ_SZ(mbox->barmem));
 	mbox->h2fq.hw_prod = OCTEP_CTRL_MBOX_H2FQ_PROD(mbox->barmem);
 	mbox->h2fq.hw_cons = OCTEP_CTRL_MBOX_H2FQ_CONS(mbox->barmem);