Comment # 6 on bug 1127339 from Takashi Iwai

... and it means that the error message is harmless and nothing to worry much.

The call efi_mem_desc_lookup() inspects whether the given area has been
reserved, so it should be OK even if it's not reserved.

The easiest "fix" would be to downgrade the message to pr_info*() or
pr_debug*() instead of pr_err*().  Or we may add a flag not to spew errors, but
I guess it's overkill.  There are only a few places calling
efi_mem_desc_lookup().  The other callers show the errors via pr_err() or
err_warn() when an error is returned from the function, so showing an error in
the function is almost superfluous.