irqflags: Fix (at least latent) code generation issue

irqflags: Fix (at least latent) code generation issue

The conditional in local_irq_restore() otherwise can cause code
bloat (the if and else blocks may get translated into separate
code paths despite the generated code being identical, dependent
on compiler internal heuristics). Note that this adjustment gets
the code in sync with the comment preceding it (which was
slightly wrong from at least from 2.6.37 onwards).

The code bloat was observed in reality with an experimental x86
patch.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/54BE5F8E02000078000570A7@mail.emea.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>