__write_overflow_field in arch/x86/kernel/apic/io_apic.c with UBSAN_INTEGER_WRAP

[nathanchance]

After the recent UBSAN_INTEGER_WRAP changes in Kees's tree, there is a warning:

$ curl -LSso .config https://src.fedoraproject.org/rpms/kernel/raw/rawhide/f/kernel-x86_64-fedora.config

$ make -skj"$(nproc)" ARCH=x86_64 LLVM=1 olddefconfig arch/x86/kernel/apic/io_apic.o
In file included from arch/x86/kernel/apic/io_apic.c:34:
In file included from include/linux/mm.h:7:
In file included from include/linux/gfp.h:7:
In file included from include/linux/mmzone.h:8:
In file included from include/linux/spinlock.h:59:
In file included from include/linux/irqflags.h:18:
In file included from arch/x86/include/asm/irqflags.h:80:
In file included from arch/x86/include/asm/paravirt.h:21:
In file included from include/linux/cpumask.h:12:
In file included from include/linux/bitmap.h:13:
In file included from include/linux/string.h:392:
include/linux/fortify-string.h:480:4: warning: call to '__write_overflow_field' declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
  480 |                         __write_overflow_field(p_size_field, size);
      |                         ^
1 warning generated.

$ make ARCH=x86_64 clean

$ curl -LSso .config https://src.fedoraproject.org/rpms/kernel/raw/rawhide/f/kernel-x86_64-fedora.config

$ scripts/config -d UBSAN_INTEGER_WRAP

$ make -skj"$(nproc)" ARCH=x86_64 LLVM=1 olddefconfig arch/x86/kernel/apic/io_apic.o

Kees mentioned it appears to be related to the SCL files.

cc @kees @JustinStitt