vfio/pci: Fix failure to close file descriptor on error

A new error path fails to close the device file descriptor when
triggered by a ballooning incompatibility within the group.  Fix it.

Fixes: 238e917285 ("vfio/ccw/pci: Allow devices to opt-in for ballooning")
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

hw/vfio/common.c

@@ -1432,6 +1432,7 @@ int vfio_get_device(VFIOGroup *group, const char *name,
         if (!QLIST_EMPTY(&group->device_list)) {
             error_setg(errp,
                        "Inconsistent device balloon setting within group");
+            close(fd);
             return -1;
         }