arm64: proton-pack: Update comment to reflect new function name

The function detect_harden_bp_fw() is gone after commit d4647f0a
("arm64: Rewrite Spectre-v2 mitigation code"). Update this comment to
reflect the new state of affairs.

Fixes: d4647f0a ("arm64: Rewrite Spectre-v2 mitigation code")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201020214544.3206838-3-swboyd@chromium.orgSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/kernel/proton-pack.c

@@ -205,8 +205,8 @@ static void install_bp_hardening_cb(bp_hardening_cb_t fn)
 				   __SMCCC_WORKAROUND_1_SMC_SZ;
 
 	/*
-	 * detect_harden_bp_fw() passes NULL for the hyp_vecs start/end if
-	 * we're a guest. Skip the hyp-vectors work.
+	 * Vinz Clortho takes the hyp_vecs start/end "keys" at
+	 * the door when we're a guest. Skip the hyp-vectors work.
 	 */
 	if (!is_hyp_mode_available()) {
 		__this_cpu_write(bp_hardening_data.fn, fn);