Fix test script

ci/run-travis.sh

@@ -16,7 +16,7 @@ if [ "$TARGET" = "arm-linux-androideabi" ]; then
   # within that image.
   docker pull alexcrichton/rust-libc-test
   docker run -v `pwd`:/clone -t alexcrichton/rust-libc-test sh ci/run.sh $TARGET
-elif [ "$TARGET" = "x86_64-unknown-linux-gnu" ]; then
+elif [ "$TARGET" = "x86_64-unknown-linux-musl" ]; then
   curl -sO https://people.mozilla.org/~acrichton/libc-test/2015-09-08/x86_64-unknown-linux-musl.tar.gz | \
     tar xzf -C $HOME/rust/lib/rustlib
   sh ci/run.sh $TARGET