IB/ehca: Returns an error on ib_copy_to_udata() failure

In case of error when writing to userspace, function ehca_create_cq()
does not set an error code before following its error path.

This patch sets the error code to -EFAULT when ib_copy_to_udata()
fails.

This was caught when using spatch (aka. coccinelle)
to rewrite call to ib_copy_{from,to}_udata().

Link: https://www.gitorious.org/opteya/coccib/source/75ebf2c1033c64c1d81df13e4ae44ee99c989eba:ib_copy_udata.cocci
Link: http://marc.info/?i=cover.1394485254.git.ydroneaud@opteya.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/ehca/ehca_cq.c

@@ -283,6 +283,7 @@ struct ib_cq *ehca_create_cq(struct ib_device *device, int cqe, int comp_vector,
 			(my_cq->galpas.user.fw_handle & (PAGE_SIZE - 1));
 		if (ib_copy_to_udata(udata, &resp, sizeof(resp))) {
 			ehca_err(device, "Copy to udata failed.");
+			cq = ERR_PTR(-EFAULT);
 			goto create_cq_exit4;
 		}
 	}