Make TPM errors less fatal

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

grub-core/lib/cmdline.c

@@ -107,6 +107,7 @@ int grub_create_loader_cmdline (int argc, char *argv[], char *buf,
 
   grub_tpm_measure ((void *)orig, grub_strlen (orig), GRUB_ASCII_PCR,
 		    "grub_kernel_cmdline", orig);
+  grub_print_error();
 
   return i;
 }