nvme-pci: fix comment typo

envent -> event.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/pci.c

@@ -372,7 +372,7 @@ static bool nvme_dbbuf_update_and_check_event(u16 value, __le32 *dbbuf_db,
 		/*
 		 * Ensure that the doorbell is updated before reading the event
 		 * index from memory.  The controller needs to provide similar
-		 * ordering to ensure the envent index is updated before reading
+		 * ordering to ensure the event index is updated before reading
 		 * the doorbell.
 		 */
 		mb();