Fix breakage I introduced in r12609, sigh.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12610 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/tests/x86_amd64_features.c b/tests/x86_amd64_features.c
index 4b78ed4..004e09c 100644
--- a/tests/x86_amd64_features.c
+++ b/tests/x86_amd64_features.c
@@ -16,6 +16,7 @@
 #define FEATURE_PRESENT       0
 #define FEATURE_NOT_PRESENT   1
 #define UNRECOGNISED_FEATURE  2
+#define USAGE_ERROR           3
 
 
 #define False  0
@@ -147,7 +148,7 @@
          else
             return FEATURE_PRESENT;
       }
-      if (cmask > 0 && (c & cmask) == dmask) {
+      if (cmask > 0 && (c & cmask) == cmask) {
          if (require_xgetbv && !have_xgetbv())
             return FEATURE_NOT_PRESENT;
          else
@@ -175,7 +176,7 @@
 {
    if ( argc != 2 ) {
       fprintf( stderr, "usage: x86_amd64_features <feature>\n" );
-      exit(3);                // Usage error.
+      exit(USAGE_ERROR);
    }
    return go(argv[1]);
 }