The sonypi_camera_command() used to fail without returning an error code if
the user fergot to enable the camera in the sonypi module (using the
camera=1 module parameter).  This caused the meye driver to apparently load
correctly but miserably fail later, when trying to access the camera for
getting some data out of it.

This patch adds an error code to sonypi_camera_command() and makes the meye
driver check for it in the PCI probe routine.  If the function fails, a
message is printed in the kernel logs reminding the user it should better
RTFM.

The patch also removes some sonypi_camera_command() commands (those
supposed to return the current camera settings) which are unreliable.  The
meye driver does not use them anyway.
Signed-off-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>