Fix xfail comment

Author: eholk

src/test/run-pass/intrinsic-atomics-cc.rs

@@ -1,7 +1,7 @@
 // xfail-fast - check-fast doesn't understand aux-build
 // aux-build:cci_intrinsic.rs
 
-// xfail-check
+// xfail-test
 
 use cci_intrinsic;
 import cci_intrinsic::atomic_xchng;