Wrong param of $len transport to the getShorContent() method of AbstractPost class when use the default phtml of postlist

[clion007]

Describe the bug
A clear and concise description of what the bug is.
Wrong param of $len transport to the getShorContent() method of AbstractPost class when use the default phtml of postlist, instanse of post was transported to getShorContent() method as the param $len, but it should be a sting param.
Preconditions:

• Magento Version: [e.g. 2.2.0]
• Module Version: [e.g. v2.10.2.2]
• PHP Version [e.g. 7.1.29]

To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
A clear and concise description of what you expected to happen.
a string param of $len should be transported.
Actual behavior
A clear and concise description of what actually happened.
instanse of post was transported to getShorContent() method as the param $len
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Additional context
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