Attempt to fix the LLVM Windows build bot lld-x86_64-win7.

llvm-svn: 224793
diff --git a/llvm/tools/llvm-objdump/MachODump.cpp b/llvm/tools/llvm-objdump/MachODump.cpp
index 1bca452..3f82812 100644
--- a/llvm/tools/llvm-objdump/MachODump.cpp
+++ b/llvm/tools/llvm-objdump/MachODump.cpp
@@ -3797,7 +3797,7 @@
   outs() << "    gs  " << format("0x%016" PRIx64, cpu64.gs) << "\n";
 }
 
-static void Print_mmst_reg(MachO::mmst_reg &r) {
+static void Print_mmst_reg(MachO::mmst_reg_t &r) {
   uint32_t f;
   outs() << "\t      mmst_reg  ";
   for (f = 0; f < 10; f++)