IB/core: Remove duplicate declaration of gid_cache_wq

Remove duplicate declaration of gid_cache_wq.

Fixes: d4186194 ("IB/core: Add generic function to extract IB speed from netdev")
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/roce_gid_mgmt.c

@@ -44,8 +44,6 @@
 
 static struct workqueue_struct *gid_cache_wq;
 
-static struct workqueue_struct *gid_cache_wq;
-
 enum gid_op_type {
 	GID_DEL = 0,
 	GID_ADD