IB/qib: Fix failure of compliance test C14-024#06_LocalPortNum

Commit 3236b2d4 ("IB/qib: MADs with misset M_Keys should return
failure") introduced a return code assignment that unfortunately
introduced an unconditional exit for the routine due to missing braces.

This patch adds the braces to correct the original patch.
Reviewed-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/qib/qib_mad.c

@@ -471,9 +471,10 @@ static int subn_get_portinfo(struct ib_smp *smp, struct ib_device *ibdev,
 		if (port_num != port) {
 			ibp = to_iport(ibdev, port_num);
 			ret = check_mkey(ibp, smp, 0);
-			if (ret)
+			if (ret) {
 				ret = IB_MAD_RESULT_FAILURE;
 				goto bail;
+			}
 		}
 	}