Mark ELF's first symbol as format specific so that llvm-nm ignores it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186860 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Object/nm-trivial-object.test b/test/Object/nm-trivial-object.test
index 5c3cc31..d517745 100644
--- a/test/Object/nm-trivial-object.test
+++ b/test/Object/nm-trivial-object.test
@@ -18,6 +18,7 @@
 COFF: 00000000 T {{_?}}main
 COFF:          U {{_?}}puts
 
+ELF-NOT:      U
 ELF:          U SomeOtherFunction
 ELF: 00000000 T main
 ELF:          U puts