error: Eliminate error_propagate() with Coccinelle, part 2

When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous commit did that with a Coccinelle script I
consider fairly trustworthy.  This commit uses the same script with
the matching of return taken out, i.e. we convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
    }

This is unsound: @err could still be read between afterwards.  I don't
know how to express "no read of @err without an intervening write" in
Coccinelle.  Instead, I manually double-checked for uses of @err.

Suboptimal line breaks tweaked manually.  qdev_realize() simplified
further to placate scripts/checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 6fde80c..2e561c0 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -292,8 +292,7 @@ static int vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
     qemu_set_fd_handler(fd, vfio_intx_interrupt, NULL, vdev);
 
     if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX, 0,
-                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
-        error_propagate(errp, err);
+                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, errp)) {
         qemu_set_fd_handler(fd, NULL, NULL, vdev);
         event_notifier_cleanup(&vdev->intx.interrupt);
         return -errno;