[llvm-readelf] Correctly dump symbols whose section id is SHN_XINDEX

Differential revision: https://reviews.llvm.org/D60614

llvm-svn: 358396
diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index 2cf2496..addebf5 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -2961,9 +2961,10 @@
   case ELF::SHN_COMMON:
     return "COM";
   case ELF::SHN_XINDEX:
-    SectionIndex = unwrapOrError(object::getExtendedSymbolTableIndex<ELFT>(
-        Symbol, FirstSym, this->dumper()->getShndxTable()));
-    LLVM_FALLTHROUGH;
+    return to_string(
+        format_decimal(unwrapOrError(object::getExtendedSymbolTableIndex<ELFT>(
+                           Symbol, FirstSym, this->dumper()->getShndxTable())),
+                       3));
   default:
     // Find if:
     // Processor specific