The irq work interrupt vector is only installed when CONFIG_X86_LOCAL_APIC is
enabled, but the interrupt handler is compiled in unconditionally.

Compile the cruft out when the APIC is disabled.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.691909010@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>