* qemu-common.h is not a system include file, so it should be included
  with "" instead of <>. Otherwise incremental builds might fail
  because only local include files are checked for changes.

* linux-user/syscall.c included the file twice.

Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Weil <weil@mail.berlios.de>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>