V4L/DVB (8253): gspca: fix warnings on x86_64

/home/v4l/master/v4l/gspca.c: In function 'gspca_frame_add':
/home/v4l/master/v4l/gspca.c:222: warning: format '%d' expects type 'int', but argument 2 has type 'long int'
/home/v4l/master/v4l/gspca.c: In function 'dev_read':
/home/v4l/master/v4l/gspca.c:1568: warning: format '%d' expects type 'int', but argument 2 has type 'size_t'
/home/v4l/master/v4l/gspca.c:1618: warning: format '%d' expects type 'int', but argument 3 has type 'size_t'

Acked-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>