[POWERPC] ps3_free_io_irq: Fix inverted error check
ps3_free_io_irq: Fix inverted error check after calling
lv1_destruct_io_irq_outlet().
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>