travis: Fail build if any command in if statement fails.

Travis is checking the exit code of the entire if statement.

Fixes: 64ffc289be ("travis: add MacOS Scons build")
Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Acked-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>

.travis.yml

@@ -53,10 +53,10 @@ install:
 script:
   - if test "x$BUILD" = xmeson; then
       meson _build -Dbuild-tests=true;
-      ninja -C _build;
-      ninja -C _build test;
+      ninja -C _build || travis_terminate 1;
+      ninja -C _build test || travis_terminate 1;
     fi
   - if test "x$BUILD" = xscons; then
-      scons;
-      scons check;
+      scons || travis_terminate 1;
+      scons check || travis_terminate 1;
     fi