iio: pressure: bmp280: fix error message for wrong chip id

The bmp280 driver also supports BMP180 which has a different chip id
with BMP280.  The probe routine verifies that the device reports the
correct chip id but the error message is confusing as if BMP280's chip
id is always expected.

Reported-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Matt Ranostay <mranostay@gmail.com>
Cc: Vlad Dogaru <vlad.dogaru@intel.com>
Cc: Christoph Mair <christoph.mair@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>