cephadm: fix timeout argument to call function

cephadm: fix timeout argument to call function

The timeout argument to call function, for executing sub-processes, did
not function - this patch makes timeout work as (probably) intended.
Use the `process.communicate()` method rather than `tee` functions to
handle IO collection. Since no logging is done until after the exit code
is known the tee calls are not necessary. Add calls to kill the child
process when the time out occurs. This helps prevent event loop "leaks"
that generate python warnings.

Signed-off-by: John Mulligan <jmulligan@redhat.com>