[IA64] acpi_get_sysname() should be __init

Section mismatch: reference to .init.text:acpi_find_rsdp
 (between 'acpi_get_sysname' and 'acpi_request_vector')

acpi_get_sysname() needs to call the __init function acpi_find_rsdp, but it
doesn't have the __init attribute itself, hence the warning. Luckily it is
only called from machvec_init() which has __init attribute, so the fix
is to define acpi_get_sysname() as __init too.
Signed-off-by: NTony Luck <tony.luck@intel.com>

arch/ia64/kernel/acpi.c

@@ -67,7 +67,8 @@ EXPORT_SYMBOL(pm_power_off);
 unsigned int acpi_cpei_override;
 unsigned int acpi_cpei_phys_cpuid;
 
-const char *acpi_get_sysname(void)
+const char __init *
+acpi_get_sysname(void)
 {
 #ifdef CONFIG_IA64_GENERIC
 	unsigned long rsdp_phys;