Fix whitespace issues

Fix whitespace issues

Remove blank lines at EOF introduced by commit
a684595c0bbd88df71285f43fb27630e3829121e,
making the project free of warnings reported by
git diff --check 4b825dc642cb6eb9a060e54bf8d69288fbee4904 HEAD

* libpam/pam_dynamic.c: Remove blank line at EOF.
* modules/pam_echo/pam_echo.c: Likewise.
* modules/pam_keyinit/pam_keyinit.c: Likewise.
* modules/pam_mkhomedir/pam_mkhomedir.c: Likewise.
* modules/pam_pwhistory/pam_pwhistory.c: Likewise.
* modules/pam_rhosts/pam_rhosts.c: Likewise.
* modules/pam_sepermit/pam_sepermit.c: Likewise.
* modules/pam_stress/pam_stress.c: Likewise.