MC: Use MachO::SectionType for MCSectionMachO::getType's return type

This is a straightfoward replacement, it makes debugging a little
easier.

This has no functional impact.

llvm-svn: 203264
diff --git a/llvm/lib/MC/MCSectionMachO.cpp b/llvm/lib/MC/MCSectionMachO.cpp
index b8e5142..2982946 100644
--- a/llvm/lib/MC/MCSectionMachO.cpp
+++ b/llvm/lib/MC/MCSectionMachO.cpp
@@ -102,7 +102,7 @@
     return;
   }
 
-  unsigned SectionType = getType();
+  MachO::SectionType SectionType = getType();
   assert(SectionType <= MachO::LAST_KNOWN_SECTION_TYPE &&
          "Invalid SectionType specified!");