qapi: Smooth another visitor error checking pattern

Convert

    visit_type_FOO(v, ..., &ptr, &err);
    ...
    if (err) {
        ...
    }

to

    visit_type_FOO(v, ..., &ptr, errp);
    ...
    if (!ptr) {
        ...
    }

for functions that set @ptr to non-null / null on success / error.

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-40-armbru@redhat.com>

1 files changed, 2 insertions, 5 deletions

diff --git a/block/ssh.c b/block/ssh.c
index f00b896..ebe3d8b 100644
--- a/block/ssh.c
+++ b/block/ssh.c
@@ -616,7 +616,6 @@ static BlockdevOptionsSsh *ssh_parse_options(QDict *options, Error **errp)
 {
     BlockdevOptionsSsh *result = NULL;
     QemuOpts *opts = NULL;
-    Error *local_err = NULL;
     const QDictEntry *e;
     Visitor *v;
 
@@ -636,11 +635,9 @@ static BlockdevOptionsSsh *ssh_parse_options(QDict *options, Error **errp)
         goto fail;
     }
 
-    visit_type_BlockdevOptionsSsh(v, NULL, &result, &local_err);
+    visit_type_BlockdevOptionsSsh(v, NULL, &result, errp);
     visit_free(v);
-
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (!result) {
         goto fail;
     }