qdev: Document qdev_prop_set_drive_err() return value

Since commit 73ac1aac39 qdev_prop_set_drive_err() returns
a boolean value. Document it.

Fixes: 73ac1aac39 "Make functions taking Error ** return bool, not void"
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200720121659.31886-1-f4bug@amsat.org>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
1 file changed