This replaces fprintf(stderr) with error_report.
This moves local variables to the beginning of the function to comply
with QEMU's coding style.
Suggested-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>