[ASTImporter] Call to HandleNameConflict in VisitEnumDecl mistakeningly using Name...

[ASTImporter] Call to HandleNameConflict in VisitEnumDecl mistakeningly using Name instead of SearchName

Summary:
https://reviews.llvm.org/D51633 added error handling to the ASTNodeImporter::VisitEnumDecl(...) for the conflicting names case. This could lead to erroneous return of an error in that case since we should have been using SearchName. Name may be empty in the case where we find the name via getTypedefNameForAnonDecl(...).

Differential Revision: https://reviews.llvm.org/D59665

llvm-svn: 357940