Make TPM errors less fatal

Handle TPM errors, and stop trying to use the TPM once we hit one.

grub-core/kern/dl.c

@@ -725,6 +725,7 @@ grub_dl_load_file (const char *filename)
   grub_file_close (file);
 
   grub_tpm_measure(core, size, GRUB_BINARY_PCR, "grub_module", filename);
+  grub_print_error();
 
   mod = grub_dl_load_core (core, size);
   grub_free (core);