KVM: x86 emulator: fix const value warning on i386 in svm insn RAX check

arch/x86/kvm/emulate.c:2598: warning: integer constant is too large for 'long' type

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Avi Kivity <avi@redhat.com>