KVM: vmx: clean up some debug output

Smatch complains about this:

    arch/x86/kvm/vmx/vmx.c:5730 dump_vmcs()
    warn: KERN_* level not at start of string

The code should be using pr_cont() instead of pr_err().

Fixes: 9d609649 ("KVM: vmx: print more APICv fields in dump_vmcs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>