error: Avoid unnecessary error_propagate() after error_setg()

Replace

    error_setg(&err, ...);
    error_propagate(errp, err);

by

    error_setg(errp, ...);

Related pattern:

    if (...) {
        error_setg(&err, ...);
        goto out;
    }
    ...
 out:
    error_propagate(errp, err);
    return;

When all paths to label out are that way, replace by

    if (...) {
        error_setg(errp, ...);
        return;
    }

and delete the label along with the error_propagate().

When we have at most one other path that actually needs to propagate,
and maybe one at the end that where propagation is unnecessary, e.g.

    foo(..., &err);
    if (err) {
        goto out;
    }
    ...
    bar(..., &err);
 out:
    error_propagate(errp, err);
    return;

move the error_propagate() to where it's needed, like

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

and transform the error_setg() as above.

In some places, the transformation results in obviously unnecessary
error_propagate().  The next few commits will eliminate them.

Bonus: the elimination of gotos will make later patches in this series
easier to review.

Candidates for conversion tracked down with this Coccinelle script:

    @@
    identifier err, errp;
    expression list args;
    @@
    -    error_setg(&err, args);
    +    error_setg(errp, args);
         ... when != err
         error_propagate(errp, err);

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-34-armbru@redhat.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index 31ec5add1d..d0d7c720a6 100644
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -2052,10 +2052,9 @@ void xen_pt_config_init(XenPCIPassthroughState *s, Error **errp)
                                                   reg_grp_offset,
                                                   &reg_grp_entry->size);
             if (rc < 0) {
-                error_setg(&err, "Failed to initialize %d/%zu, type = 0x%x,"
+                error_setg(errp, "Failed to initialize %d/%zu, type = 0x%x,"
                            " rc: %d", i, ARRAY_SIZE(xen_pt_emu_reg_grps),
                            xen_pt_emu_reg_grps[i].grp_type, rc);
-                error_propagate(errp, err);
                 xen_pt_config_delete(s);
                 return;
             }