mtd: m25p80: Reinstate error print on unrecognized flash

Commit b34bc037b26e621e5fc13466767e4da110a7b3d3 removed the
"unrecognized JEDEC id" error message, causing the probe function to
silently abort if the flash ID is unrecognized.

It is desirable to produce diagnostic output in this situation so that
the user has some idea what went wrong.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/devices/m25p80.c

@@ -764,6 +764,7 @@ static const struct spi_device_id *__devinit jedec_probe(struct spi_device *spi)
 			return &m25p_ids[tmp];
 		}
 	}
+	dev_err(&spi->dev, "unrecognized JEDEC id %06x\n", jedec);
 	return ERR_PTR(-ENODEV);
 }