This change adds return code to spdk_subsystem_init().
Making it's caller responsible for handling application
state - such as calling spdk_app_stop().
This change implies that start_subsystem_init RPC does not
stop the application on failure, only reports back the error.
Renamed g_app_start/stop variables to now more relevant
g_subsystem_start/stop.
Change-Id: I66a7da6ecfb234a569c65279cc4b210ddac53d2a
Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/464412
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
b85881ec7c