Fix typo noticed by Chris.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63449 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Driver/clang.cpp b/Driver/clang.cpp
index 52f3478..fe5e7f8 100644
--- a/Driver/clang.cpp
+++ b/Driver/clang.cpp
@@ -486,7 +486,7 @@
               llvm::cl::desc("Store string literals as writable data"));
 
 static llvm::cl::opt<bool>
-NoLaxVectorConversions("fnolax-vector-conversions",
+NoLaxVectorConversions("fno-lax-vector-conversions",
                        llvm::cl::desc("Disallow implicit conversions between "
                                       "vectors with a different number of "
                                       "elements or different element types"));