KVM: introduce KVM_PFN_ERR_BAD

Then, remove get_bad_pfn

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 840f44a..b2cf310 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -50,6 +50,7 @@
 
 #define KVM_PFN_ERR_FAULT	(-EFAULT)
 #define KVM_PFN_ERR_HWPOISON	(-EHWPOISON)
+#define KVM_PFN_ERR_BAD		(-ENOENT)
 
 /*
  * vcpu->requests bit members