Fixed Context::enable_probe method. (#2006)
Fixed Context::enable_probe method. (#2006)

Fixed Context::enable_probe method so that it does not discard the result of Probe::enable.
iovisor/bcc,mcaleavya/bcc,iovisor/bcc,iovisor/bcc,brendangregg/bcc,mcaleavya/bcc,brendangregg/bcc,iovisor/bcc,tuxology/bcc,brendangregg/bcc,tuxology/bcc,tuxology/bcc,mcaleavya/bcc,brendangregg/bcc,brendangregg/bcc,mcaleavya/bcc,mcaleavya/bcc,iovisor/bcc,tuxology/bcc,tuxology/bcc