Fix typoed cast to avoid assertion in MCFragment::dump.

llvm-svn: 334959
diff --git a/llvm/lib/MC/MCFragment.cpp b/llvm/lib/MC/MCFragment.cpp
index 01ad640..0ebcf21 100644
--- a/llvm/lib/MC/MCFragment.cpp
+++ b/llvm/lib/MC/MCFragment.cpp
@@ -334,7 +334,7 @@
 
   OS << "<MCFragment " << (const void *)this << " LayoutOrder:" << LayoutOrder
      << " Offset:" << Offset << " HasInstructions:" << hasInstructions();
-  if (const MCEncodedFragment *EF = cast<MCEncodedFragment>(this))
+  if (const MCEncodedFragment *EF = dyn_cast<MCEncodedFragment>(this))
     OS << " BundlePadding:" << static_cast<unsigned>(EF->getBundlePadding());
   OS << ">";