kernel-shark: Make KsSession::importFromFile return status flag

The function has a better handling of the case when the session
description file cannot be loaded. It returns true on success,
otherwise false. We need this return flag in order to provide
adequate error message in the case when this operation fails.

Link: http://lore.kernel.org/linux-trace-devel/20190314151012.905-4-ykaradzhov@vmware.com

Signed-off-by: Yordan Karadzhov <ykaradzhov@vmware.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2 files changed