atoi() doesn't detect errors. There is no way to know that a 0 return
is correct conversion or due to an error.

Introduce atoi_paranoid() to detect errors and provide correct
conversion. Replace all atoi() calls with atoi_paranoid().
Signed-off-by: NVipin Sharma <vipinsh@google.com>
Suggested-by: NDavid Matlack <dmatlack@google.com>
Suggested-by: NSean Christopherson <seanjc@google.com>
Reviewed-by: NSean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221103191719.1559407-4-vipinsh@google.comSigned-off-by: NSean Christopherson <seanjc@google.com>