scripts/sorttable: Use a structure of function pointers for elf helpers

scripts/sorttable: Use a structure of function pointers for elf helpers

Instead of having a series of function pointers that gets assigned to the
Elf64 or Elf32 versions, put them all into a single structure and use
that. Add the helper function that chooses the structure into the macros
that build the different versions of the elf functions.

Link: https://lore.kernel.org/all/CAHk-=wiafEyX7UgOeZgvd6fvuByE5WXUPh9599kwOc_d-pdeug@mail.gmail.com/
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/20250110075459.13d4b94c@gandalf.local.home
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>