kvm: debugfs: fix memory leak in kvm_create_vm_debugfs

In commit bc9e9e67 ("KVM: debugfs: Reuse binary stats descriptors")
loop for filling debugfs_stat_data was copy-pasted 2 times, but
in the second loop pointers are saved over pointers allocated
in the first loop.  All this causes is a memory leak, fix it.

Fixes: bc9e9e67

 ("KVM: debugfs: Reuse binary stats descriptors")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210701195500.27097-1-paskripkin@gmail.com>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>