RDMA/qib: Remove useless qib_read_ureg() function

Fix the following clang warning:

drivers/infiniband/hw/qib/qib_iba7322.c:803:19: warning: unused function 'qib_read_ureg' [-Wunused-function].

Link: https://lore.kernel.org/r/1618305063-29007-1-git-send-email-jiapeng.chong@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/qib/qib_iba7322.c

@@ -790,28 +790,6 @@ static inline u32 qib_read_ureg32(const struct qib_devdata *dd,
 		 (char __iomem *)dd->kregbase + dd->uregbase)));
 }
 
-/**
- * qib_read_ureg - read virtualized per-context register
- * @dd: device
- * @regno: register number
- * @ctxt: context number
- *
- * Return the contents of a register that is virtualized to be per context.
- * Returns -1 on errors (not distinguishable from valid contents at
- * runtime; we may add a separate error variable at some point).
- */
-static inline u64 qib_read_ureg(const struct qib_devdata *dd,
-				enum qib_ureg regno, int ctxt)
-{
-
-	if (!dd->kregbase || !(dd->flags & QIB_PRESENT))
-		return 0;
-	return readq(regno + (u64 __iomem *)(
-		(dd->ureg_align * ctxt) + (dd->userbase ?
-		 (char __iomem *)dd->userbase :
-		 (char __iomem *)dd->kregbase + dd->uregbase)));
-}
-
 /**
  * qib_write_ureg - write virtualized per-context register
  * @dd: device