Revert "Auto merge of rust-lang#53134 - alexcrichton:tweak-travis, r=Mark-Simulacrum"

This reverts commit f9b9b6e, reversing
changes made to 45a9d41.

Author: kennytm

.travis.yml

@@ -278,8 +278,6 @@ after_success:
       du . | sort -nr | head -n100
 
 after_failure:
-  # Requested by travis to debug "shutting down NOW" errors
-  - sudo tail -n 500 /var/log/syslog
   - >
       echo "#### Build failed; Disk usage after running script:";
       df -h;