[MTD] m25p80: fix detection of m25p16 flashes

Commit d0e8c47c ("m25p80.c extended jedec
support") added support for extended ids but seems to break on flashes
which don't have an extended id defined.  If the table does not have an
extid defined, then we should ignore it.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NMichael Hennerich <Michael.Hennerich@analog.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/devices/m25p80.c

@@ -575,7 +575,7 @@ static struct flash_info *__devinit jedec_probe(struct spi_device *spi)
 			tmp < ARRAY_SIZE(m25p_data);
 			tmp++, info++) {
 		if (info->jedec_id == jedec) {
-			if (ext_jedec != 0 && info->ext_id != ext_jedec)
+			if (info->ext_id != 0 && info->ext_id != ext_jedec)
 				continue;
 			return info;
 		}