[PULL 16/32] fdc: Fix fallback=auto error handling

[Markus Armbruster <armbru@redhat.com>]

fdctrl_realize_common() rejects fallback=auto.  Used by devices
"isa-fdc", "sysbus-fdc", "SUNW,fdtwo".  The error handling is broken:

    $ qemu-system-x86_64 -nodefaults -device isa-fdc,fallback=auto,driveA=fd0 -drive if=none,id=fd0
    **
    ERROR:/work/armbru/qemu/hw/block/fdc.c:434:pick_drive_type: assertion failed: (drv->drive != FLOPPY_DRIVE_TYPE_AUTO)
    Aborted (core dumped)

Cause: fdctrl_realize_common() neglects to bail out after setting the
error.  Fix that.

Fixes: a73275dd6fc3bfda33165bebc28e0c33c20cb0a0
Cc: John Snow <jsnow@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200422130719.28225-7-armbru@redhat.com>
---
 hw/block/fdc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/block/fdc.c b/hw/block/fdc.c
index 33bc9e2f92..9628cc171e 100644
--- a/hw/block/fdc.c
+++ b/hw/block/fdc.c
@@ -2615,6 +2615,7 @@ static void fdctrl_realize_common(DeviceState *dev, FDCtrl *fdctrl,
 
     if (fdctrl->fallback == FLOPPY_DRIVE_TYPE_AUTO) {
         error_setg(errp, "Cannot choose a fallback FDrive type of 'auto'");
+        return;
     }
 
     /* Fill 'command_to_handler' lookup table */
-- 
2.21.1