Update exit code and prompt summary
Update exit code and prompt summary

Update exit code to 1 if error is found. In addition, it will now show
how many errors are found if there is any.

Signed-off-by: Chin Yeung Li <6ccf8ba77c1e60cfc87b1db28da7a91e12151748@nexb.com>
dejacode/about-code-tool,dejacode/about-code-tool