arm64: proton-pack: Drop print when !CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY

Following the pattern established with other Spectre mitigations,
do not print a message when the CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
Kconfig option is disabled.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: shechenglong <shechenglong@xfusion.com>
Signed-off-by: Will Deacon <will@kernel.org>

Author: shechenglong-fusion

arch/arm64/kernel/proton-pack.c

@@ -1042,8 +1042,6 @@ void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *entry)
 
 	if (arm64_get_spectre_v2_state() == SPECTRE_VULNERABLE) {
 		/* No point mitigating Spectre-BHB alone. */
-	} else if (!IS_ENABLED(CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY)) {
-		pr_info_once("spectre-bhb mitigation disabled by compile time option\n");
 	} else if (cpu_mitigations_off() || __nospectre_bhb) {
 		pr_info_once("spectre-bhb mitigation disabled by command line option\n");
 	} else if (supports_ecbhb(SCOPE_LOCAL_CPU)) {