Use ELFOSABI_NONE. This matches both bfd ld and gold.

llvm-svn: 244033
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index 0f6adc9..91cb16e 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -123,7 +123,7 @@
   EHdr->e_ident[EI_CLASS] = ELFCLASS64;
   EHdr->e_ident[EI_DATA] = ELFDATA2LSB;
   EHdr->e_ident[EI_VERSION] = EV_CURRENT;
-  EHdr->e_ident[EI_OSABI] = ELFOSABI_GNU;
+  EHdr->e_ident[EI_OSABI] = ELFOSABI_NONE;
 
   EHdr->e_type = ET_EXEC;
   EHdr->e_machine = EM_X86_64;
diff --git a/lld/test/elf2/basic.test b/lld/test/elf2/basic.test
index 52e35bd..7fe5674 100644
--- a/lld/test/elf2/basic.test
+++ b/lld/test/elf2/basic.test
@@ -16,7 +16,7 @@
 # CHECK-NEXT:     Class: 64-bit (0x2)
 # CHECK-NEXT:     DataEncoding: LittleEndian (0x1)
 # CHECK-NEXT:     FileVersion: 1
-# CHECK-NEXT:     OS/ABI: GNU/Linux (0x3)
+# CHECK-NEXT:     OS/ABI: SystemV (0x0)
 # CHECK-NEXT:     ABIVersion: 0
 # CHECK-NEXT:     Unused: (00 00 00 00 00 00 00)
 # CHECK-NEXT:   }