kernel-shark: Remove hard-coded install paths

The definitions of KS_APP_NAME and KS_ICON are used to derive standard
installation paths for the KernelShark libraries, plugins and icons.
The patch combines improvements suggested by Troy Engel and Bas van Dijk.

Link: http://lore.kernel.org/linux-trace-devel/20190515190911.20755-2-ykaradzhov@vmware.com

Suggested-by: Troy Engel <troyengel@gmail.com>
Suggested-by: Bas van Dijk <v.dijk.bas@gmail.com>
Signed-off-by: Yordan Karadzhov <ykaradzhov@vmware.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>