kernelshark: Update the README for changes to the make process

The top level git tree's Makefile has code added to build the cmake portion
of KernelShark. But the README does not document the process. Bring the
README up to speed with how to actually build KernelShark.

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