tpm-backend: Remove unneeded member variable from backend class

TPMDriverOps inside TPMBackend is not required, as it is supposed to be a class
member. The only possible reason for keeping in TPMBackend was, to get the
backend type in tpm.c where dedicated backend api, tpm_backend_get_type() is
present.

Signed-off-by: Amarnath Valluri <amarnath.valluri@intel.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

hw/tpm/tpm_passthrough.c

@@ -46,8 +46,6 @@
 #define TPM_PASSTHROUGH(obj) \
     OBJECT_CHECK(TPMPassthruState, (obj), TYPE_TPM_PASSTHROUGH)
 
-static const TPMDriverOps tpm_passthrough_driver;
-
 /* data structures */
 typedef struct TPMPassthruThreadParams {
     TPMState *tpm_state;
@@ -462,8 +460,6 @@ static TPMBackend *tpm_passthrough_create(QemuOpts *opts, const char *id)
     /* let frontend set the fe_model to proper value */
     tb->fe_model = -1;
 
-    tb->ops = &tpm_passthrough_driver;
-
     if (tpm_passthrough_handle_device_opts(opts, tb)) {
         goto err_exit;
     }

include/sysemu/tpm_backend.h

@@ -50,7 +50,6 @@ struct TPMBackend {
     enum TpmModel fe_model;
     char *path;
     char *cancel_path;
-    const TPMDriverOps *ops;
 
     QLIST_ENTRY(TPMBackend) list;
 };

tpm.c

@@ -211,7 +211,7 @@ static TPMInfo *qmp_query_tpm_inst(TPMBackend *drv)
     res->model = drv->fe_model;
     res->options = g_new0(TpmTypeOptions, 1);
 
-    switch (drv->ops->type) {
+    switch (tpm_backend_get_type(drv)) {
     case TPM_TYPE_PASSTHROUGH:
         res->options->type = TPM_TYPE_OPTIONS_KIND_PASSTHROUGH;
         tpo = g_new0(TPMPassthroughOptions, 1);