staging: media: ompa4iss: Replace sprintf with snprintf

This patch replaces sprintf with snprintf as sprintf does
not check for buffer overflow.

Signed-off-by: Tapasweni Pathak <tapaswenipathak@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>