tpm: Exit in reset when backend indicates failure

Exit() in the frontend reset function when the backend indicates
intialization failure.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

hw/tpm/tpm_crb.c

@@ -273,7 +273,9 @@ static void tpm_crb_reset(void *dev)
     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->tpmbe),
                             CRB_CTRL_CMD_SIZE);
 
-    tpm_backend_startup_tpm(s->tpmbe, s->be_buffer_size);
+    if (tpm_backend_startup_tpm(s->tpmbe, s->be_buffer_size) < 0) {
+        exit(1);
+    }
 }
 
 static void tpm_crb_realize(DeviceState *dev, Error **errp)

hw/tpm/tpm_tis.c

@@ -910,7 +910,9 @@ static void tpm_tis_reset(DeviceState *dev)
         s->rw_offset = 0;
     }
 
-    tpm_backend_startup_tpm(s->be_driver, s->be_buffer_size);
+    if (tpm_backend_startup_tpm(s->be_driver, s->be_buffer_size) < 0) {
+        exit(1);
+    }
 }
 
 /* persistent state handling */