IB/hfi1: Get rid of a warning

The right markup for a variable is @foo, and not @foo[].

Using a wrong markup caused this warning:

	./drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h:243: WARNING: Inline strong start-string without end-string.

Link: https://lore.kernel.org/r/9dce702510505556d75a13d9641e09218a4b4a65.1584456635.git.mchehab+huawei@kernel.orgSigned-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.h

@@ -239,7 +239,7 @@ struct opa_veswport_mactable_entry {
  * @offset: mac table starting offset
  * @num_entries: Number of entries to get or set
  * @mac_tbl_digest: mac table digest
- * @tbl_entries[]: Array of table entries
+ * @tbl_entries: Array of table entries
  *
  * The EM sends down this structure in a MAD indicating
  * the starting offset in the forwarding table that this