Update comment to match the macro name (#72)

diff --git a/test/aarch64/test-abi.cc b/test/aarch64/test-abi.cc
index e823c7e..d6b1563 100644
--- a/test/aarch64/test-abi.cc
+++ b/test/aarch64/test-abi.cc
@@ -112,4 +112,4 @@
 }
 }  // namespace vixl::aarch64
 
-#endif  // VIXL_ABI_SUPORT
+#endif  // VIXL_HAS_ABI_SUPPORT