RDMA/ocrdma: Use unsigned for bit index

In the expressions idx/32 and idx%32, both idx and 32 have signed
type, and unfortunately the C standard prescribes rounding to 0, so
unless gcc can prove that idx is non-negative, these cannot be
implemented as simple shift respectively mask operations. Help gcc by
changing the type of idx to unsigned - this cuts another few
instructions from the generated code.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Selvin Xavier <selvin.xavier@emulex.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/ocrdma/ocrdma_verbs.c

@@ -1586,10 +1586,10 @@ int ocrdma_query_qp(struct ib_qp *ibqp,
 	return status;
 }
 
-static void ocrdma_srq_toggle_bit(struct ocrdma_srq *srq, int idx)
+static void ocrdma_srq_toggle_bit(struct ocrdma_srq *srq, unsigned int idx)
 {
-	int i = idx / 32;
-	unsigned int mask = (1 << (idx % 32));
+	unsigned int i = idx / 32;
+	u32 mask = (1U << (idx % 32));
 
 	srq->idx_bit_fields[i] ^= mask;
 }