x86/apic: Fix a comment in init_apic_mappings()

commit c0104d38 ("x86, apic: Unify identical register_lapic_address()
functions") renames acpi_register_lapic_address to register_lapic_address.

But acpi_register_lapic_address remains in a comment, and renaming it to
register_lapic_address is not suitable for this comment.

Remove acpi_register_lapic_address and rewrite the comment.

[ tglx: LAPIC address can be registered either by ACPI/MADT or MP info ]
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/1488805690-5055-1-git-send-email-douly.fnst@cn.fujitsu.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/apic/apic.c

@@ -1789,8 +1789,8 @@ void __init init_apic_mappings(void)
 		apic_phys = mp_lapic_addr;
 
 		/*
-		 * acpi lapic path already maps that address in
-		 * acpi_register_lapic_address()
+		 * If the system has ACPI MADT tables or MP info, the LAPIC
+		 * address is already registered.
 		 */
 		if (!acpi_lapic && !smp_found_config)
 			register_lapic_address(apic_phys);