[gcc] Fix SIGSEGV in computed goto compilation.

BUG=http://code.google.com/p/nativeclient/issues/detail?id=601
TEST=

Review URL: http://codereview.chromium.org/3345011
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 0c827b4..e00d5a9 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -15278,7 +15278,7 @@
 {
   if (TARGET_64BIT)
     {
-      "nacljmp\t%k0,%%r15";
+      return "nacljmp\t%k0,%%r15";
     }
   else
     {