x86: irqinit_32.c fix compilation warning

Fix:

  arch/x86/kernel/irqinit_32.c:124: warning: 'smp_intr_init' defined but not used

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>