x86/apic: Remove local var in flat_send_IPI_allbutself()

No code changed:

  # arch/x86/kernel/apic/apic_flat_64.o:

   text    data     bss     dec     hex filename
   1838     624       0    2462     99e apic_flat_64.o.before
   1838     624       0    2462     99e apic_flat_64.o.after

md5:
   aa2ae687d94bc4534f86ae6865dabd6a  apic_flat_64.o.before.asm
   42148da76ba8f9a236c33f8803bd2a6b  apic_flat_64.o.after.asm

md5 sum is different due to asm output offsets changing.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171211115444.26577-1-bp@alien8.de


Signed-off-by: Ingo Molnar <mingo@kernel.org>