Fix a funny typo.

Thanks for j`ey and Sean Silva for noticing it.

llvm-svn: 196344
diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
index 9671bcb..5ae2d92 100644
--- a/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -845,7 +845,7 @@
 
   Header.PointerToSymbolTable = offset;
 
-  // We want a deterministic output. It looks like GUN as also writes 0 in here.
+  // We want a deterministic output. It looks like GNU as also writes 0 in here.
   Header.TimeDateStamp = 0;
 
   // Write it all to disk...