Revert "More fixes to get good error messages for bad archives."

This reverts commit r277540. It breaks the build with:

../lib/Object/Archive.cpp:264:41: error: return type of out-of-line definition of 'llvm::object::ArchiveMemberHeader::getUID' differs from that in the declaration
Expected<unsigned> ArchiveMemberHeader::getUID() const {
~~~~~~~~~~~~~~~~~~                      ^
include/llvm/Object/Archive.h:53:12: note: previous declaration is here
  unsigned getUID() const;
  ~~~~~~~~ ^

llvm-svn: 277627
diff --git a/llvm/tools/dsymutil/BinaryHolder.cpp b/llvm/tools/dsymutil/BinaryHolder.cpp
index 579ffc2..abb4ea0 100644
--- a/llvm/tools/dsymutil/BinaryHolder.cpp
+++ b/llvm/tools/dsymutil/BinaryHolder.cpp
@@ -106,11 +106,8 @@
     for (auto Child : CurrentArchive->children(Err)) {
       if (auto NameOrErr = Child.getName()) {
         if (*NameOrErr == Filename) {
-          Expected<sys::TimeValue> ModTimeOrErr = Child.getLastModified();
-          if (!ModTimeOrErr)
-            return errorToErrorCode(ModTimeOrErr.takeError());
           if (Timestamp != sys::TimeValue::PosixZeroTime() &&
-              Timestamp != ModTimeOrErr.get()) {
+              Timestamp != Child.getLastModified()) {
             if (Verbose)
               outs() << "\tmember had timestamp mismatch.\n";
             continue;