Simplify PDiag's move assignment overload a bit, the self-move check isn't actually necessary.

This just empties out the diag, which is fine.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169542 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/PartialDiagnostic.h b/include/clang/Basic/PartialDiagnostic.h
index 63363a9..0ac4296 100644
--- a/include/clang/Basic/PartialDiagnostic.h
+++ b/include/clang/Basic/PartialDiagnostic.h
@@ -253,17 +253,13 @@
 
 #if LLVM_HAS_RVALUE_REFERENCES
   PartialDiagnostic &operator=(PartialDiagnostic &&Other) {
-    if (this != &Other) {
-      if (DiagStorage)
-        freeStorage();
+    freeStorage();
 
-      DiagID = Other.DiagID;
-      DiagStorage = Other.DiagStorage;
-      Allocator = Other.Allocator;
+    DiagID = Other.DiagID;
+    DiagStorage = Other.DiagStorage;
+    Allocator = Other.Allocator;
 
-      Other.DiagStorage = 0;
-    }
-
+    Other.DiagStorage = 0;
     return *this;
   }
 #endif