[OPENMP] Restore allowing of braced initializers in the declare reduction
    init.

Braced initializers were not accepted after the last fix in the initialier.Restored previous functionality.
diff --git a/clang/lib/Parse/ParseOpenMP.cpp b/clang/lib/Parse/ParseOpenMP.cpp
index a62c68b..aaef4cd 100644
--- a/clang/lib/Parse/ParseOpenMP.cpp
+++ b/clang/lib/Parse/ParseOpenMP.cpp
@@ -430,7 +430,7 @@
     }
 
     PreferredType.enterVariableInit(Tok.getLocation(), OmpPrivParm);
-    ExprResult Init = ParseAssignmentExpression();
+    ExprResult Init = ParseInitializer();
 
     if (Init.isInvalid()) {
       SkipUntil(tok::r_paren, tok::annot_pragma_openmp_end, StopBeforeMatch);