Fix chart update ebpf.plugin

[thiagoftsm]

Summary

Fixes #13346

This PR is bringing the following changes to remove locks that do not allow chart to be updated correctly:

1. Change else to else if in systemd charts, this will avoid to recreate these charts every iteration
2. Use secondary mutex only when thread is integrated with apps' and cgroup` will work more independent.
3. Remove calls to functions broadcast and wait, because they were creating delay to send the messages to netdata on environments tested

Test Plan

1. Compile current master branch and run netdata with ebpf.plugin enabled during few minutes
2. Run the following command and verify that you will have value different than 0:

$ grep rrdset_done /var/log/netdata/error.log  | grep ebpf | wc -l
456

3. Stop netdata
4. Compile this branch
5. Run step 2 again:

$ grep rrdset_done /var/log/netdata/error.log  | grep ebpf | wc -l
0

Additional Information

This PR was tested on the following environments:

database	branch	result
map	master	Errors appear
dbengine	master	error appear
dbengine	this branch	After this commit with all threads not related to apps/cgroup disabled, error did not appear
dbengine	this branch	All threads enabled, I had only 9 errors, but this happened when parent was overload, and child was a VM
dbengine with 2 Tier	this Branch	like previous
map	this branch	All threads enabled.
ram	this branch	All threads enabled. When I ran on parent I did not have any error.

Map is the memory mode where I had more events, and I still have when my parent was overloaded or updating Tier.

For users: How does this change affect me?

Describe the PR affects users: - Which area of Netdata is affected by the change? ebpf.plugin - Can they see the change or is it an under the hood? If they can see it, where? Due the fact netdata interpolates, it was not visible when a data was not stored on dashboard, but this is visible trough our API. - How is the user impacted by the change? All collected data will be stored in the correct time, unless system is overloaded, but this also affects other plugins. - What are there any benefits of the change? Data quality

[DShreve2]

Docs approve.