x86/alternatives: Move the text_poke_array manipulation into text_poke_int3_loc_init...

x86/alternatives: Move the text_poke_array manipulation into text_poke_int3_loc_init() and rename it to __smp_text_poke_batch_add()

This simplifies the code and code generation a bit:

   text	   data	    bss	    dec	    hex	filename
  14802	   1029	   4112	  19943	   4de7	alternative.o.before
  14784	   1029	   4112	  19925	   4dd5	alternative.o.after

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250411054105.2341982-36-mingo@kernel.org