Fixed grammatical error.

llvm-svn: 7160
diff --git a/llvm/lib/Support/CommandLine.cpp b/llvm/lib/Support/CommandLine.cpp
index fa67a8a..f508483 100644
--- a/llvm/lib/Support/CommandLine.cpp
+++ b/llvm/lib/Support/CommandLine.cpp
@@ -216,7 +216,7 @@
 
     // Check to see if this is a positional argument.  This argument is
     // considered to be positional if it doesn't start with '-', if it is "-"
-    // itself, or if we have see "--" already.
+    // itself, or if we have seen "--" already.
     //
     if (argv[i][0] != '-' || argv[i][1] == 0 || DashDashFound) {
       // Positional argument!