staging: sm750fb: lynxfb_pci_probe: return actual errors

The lynxfb_pci_probe always returned -ENODEV in case of error. Modify it
so that actual error code will be propogated to the caller.

Signed-off-by: Mike Rapoport <mike.rapoport@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>