staging/easycap: remove EASYCAP_SILENT option

This has simulated a fault condition of probing for audio capability

Cc: Mike Thomas <rmthomas@sciolus.org>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>