arm: Clean up fragile use of error_is_set() in realize() methods

Using error_is_set(ERRP) to find out whether a function failed is
either wrong, fragile, or unnecessarily opaque.  It's wrong when ERRP
may be null, because errors go undetected when it is.  It's fragile
when proving ERRP non-null involves a non-local argument.  Else, it's
unnecessarily opaque (see commit 84d18f0).

I guess the error_is_set(errp) in the DeviceClass realize() methods
are merely fragile right now, because I can't find a call chain that
passes a null errp argument.

Make the code more robust and more obviously correct: receive the
error in a local variable, then propagate it through the parameter.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
MAINTAINERS: Document QOM

Invented by Anthony. Maintained through my qom-next tree lately.

Cc: Anthony Liguori <aliguori@amazon.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
MAINTAINERS: Take maintainership for QTest

Invented by Anthony. Maintenance has been handled by me lately.

Note that the tests themselves are intentionally not part of this entry;
they are considered part of the device or subsystem they are covering.

Cc: Anthony Liguori <aliguori@amazon.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
MAINTAINERS: Document I2C libqos

Written by me for TMP105 testing.

Signed-off-by: Andreas Färber <afaerber@suse.de>
qtest: Assure that init_socket()'s listen() does not fail

In practice this seems very unlikely, so cleanup is neglected, as done
for bind().

Signed-off-by: Andreas Färber <afaerber@suse.de>
qtest: Add error reporting to socket_accept()

We're not using the GLib infrastructure here, to allow cleaning up the
sockets. Still, knowing why a certain test run failed can be valuable.

Signed-off-by: Andreas Färber <afaerber@suse.de>
qtest: Be paranoid about accept() addrlen argument

POSIX specifies that address_len shall on output specify the length of
the stored address; it does not however specify whether it may get
updated on failure as well to, e.g., zero.

In case EINTR occurs, re-initialize the variable to the desired value.

Cc: Eric Blake <eblake@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
tests: Add ac97 qtest

Signed-off-by: Andreas Färber <afaerber@suse.de>
tests: Add es1370 qtest

Signed-off-by: Andreas Färber <afaerber@suse.de>
tests: Add intel-hda qtests

Test both the ich6 and the ich9 version (cf. q35 config) and all the
codecs.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
tests: Add ioh3420 qtest

Signed-off-by: Andreas Färber <afaerber@suse.de>
tests: Add EHCI qtest

Signed-off-by: Andreas Färber <afaerber@suse.de>