Revert "vga: don't abort when adding a duplicate isa-vga device"

This reverts commit 7852a77f.

The check is bogus as it ends up finding itself and falling over.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/733


Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211206095209.2332376-1-alex.bennee@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

hw/display/vga-isa.c

@@ -33,7 +33,6 @@
 #include "hw/loader.h"
 #include "hw/qdev-properties.h"
 #include "qom/object.h"
-#include "qapi/error.h"
 
 #define TYPE_ISA_VGA "isa-vga"
 OBJECT_DECLARE_SIMPLE_TYPE(ISAVGAState, ISA_VGA)
@@ -62,15 +61,6 @@ static void vga_isa_realizefn(DeviceState *dev, Error **errp)
     MemoryRegion *vga_io_memory;
     const MemoryRegionPortio *vga_ports, *vbe_ports;
 
-    /*
-     * make sure this device is not being added twice, if so
-     * exit without crashing qemu
-     */
-    if (object_resolve_path_type("", TYPE_ISA_VGA, NULL)) {
-        error_setg(errp, "at most one %s device is permitted", TYPE_ISA_VGA);
-        return;
-    }
-
     s->global_vmstate = true;
     vga_common_init(s, OBJECT(dev));
     s->legacy_address_space = isa_address_space(isadev);