Fix some issues in apps/req
Fix some issues in apps/req

1. the 'ignore -days' warning should not be printed without '-x509'
2. the 'ignore -days' warning should terminate with new-line

Reviewed-by: Tim Hudson <eb0be8e447f673b41b10eda09d63cd72526b0a42@openssl.org>
Reviewed-by: Richard Levitte <5fb523282dd7956571c80524edc2dccfa0bd8234@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4767)

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl