Make TPM errors less fatal

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

grub-core/script/execute.c

@@ -963,6 +963,7 @@ grub_script_execute_cmdline (struct grub_script_cmd *cmd)
   cmdstring[cmdlen-1]= '\0';
   grub_tpm_measure ((unsigned char *)cmdstring, cmdlen, GRUB_ASCII_PCR,
 		    "grub_cmd", cmdstring);
+  grub_print_error();
   grub_free(cmdstring);
   invert = 0;
   argc = argv.argc - 1;