board/common: disable unused pam_lastlog.so from PAM login

Fixes the following recurring login warning in syslog.  (We cannot use
pam_lastlog.so since it does not rotate its /var/log/lastlog file.)

login[2819]: PAM unable to dlopen(/lib/security/pam_lastlog.so): /lib/security/pam_lastlog.so: cannot open shared object file: No such file or directory

Follow-up to issue #542

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

board/common/post-build.sh

@@ -110,6 +110,9 @@ if [ -L "$TARGET_DIR/var/lib/avahi-autoipd" ]; then
 	mkdir "$TARGET_DIR/var/lib/avahi-autoipd"
 fi
 
+# Drop Buildroot default pam_lastlog.so from login chain
+sed -i '/^[^#]*pam_lastlog.so/s/^/# /' "$TARGET_DIR/etc/pam.d/login"
+
 # Allow pdmenu (setup) and bash to be login shells, bash is added
 # automatically when selected in menuyconfig, but not when BusyBox
 # provides a symlink (for ash).  The /bin/{true,false} are old UNIX