kallsyms: exclude kasan local symbols on s390

gcc asan instrumentation emits the following sequence to store frame pc
when the kernel is built with CONFIG_RELOCATABLE:
debug/vsprintf.s:
        .section        .data.rel.ro.local,"aw"
        .align  8
.LC3:
        .quad   .LASANPC4826@GOTOFF
.text
        .align  8
        .type   number, @function
number:
.LASANPC4826:

and in case reloc is issued for LASANPC label it also gets into .symtab
with the same address as actual function symbol:
$ nm -n vmlinux | grep 0000000001397150
0000000001397150 t .LASANPC4826
0000000001397150 t number

In the end kernel backtraces are almost unreadable:
[  143.748476] Call Trace:
[  143.748484] ([<000000002da3e62c>] .LASANPC2671+0x114/0x190)
[  143.748492]  [<000000002eca1a58>] .LASANPC2612+0x110/0x160
[  143.748502]  [<000000002de9d830>] print_address_description+0x80/0x3b0
[  143.748511]  [<000000002de9dd64>] __kasan_report+0x15c/0x1c8
[  143.748521]  [<000000002ecb56d4>] strrchr+0x34/0x60
[  143.748534]  [<000003ff80...