[MTD] [NAND] Work around false compiler warning in CAFÉ driver

drivers/mtd/nand/cafe.c: In function 'cafe_nand_cmdfunc':
drivers/mtd/nand/cafe.c:269: warning: 'irqs' may be used uninitialized in this function

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>