The xc_get_frequency_error() function reported the frequency error
incorrectly. The data read from the hardware is a signed integer, in
15625 Hz units. The attached patch fixes the bug.
Signed-off-by: Istvan Varga <istvan_v@mailbox.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>