[RISCV] Fix build after r315254

createELFObjectWriter now takes a std::unique_ptr<MCELFObjectTargetWriter> 
rather than a MCELFObjectTargetWriter*.

llvm-svn: 315275
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp
index 95d4242..6319db8 100644
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp
@@ -63,6 +63,7 @@
 
 MCObjectWriter *llvm::createRISCVELFObjectWriter(raw_pwrite_stream &OS,
                                                  uint8_t OSABI, bool Is64Bit) {
-  MCELFObjectTargetWriter *MOTW = new RISCVELFObjectWriter(OSABI, Is64Bit);
-  return createELFObjectWriter(MOTW, OS, /*IsLittleEndian*/ true);
+  return createELFObjectWriter(
+      llvm::make_unique<RISCVELFObjectWriter>(OSABI, Is64Bit), OS,
+      /*IsLittleEndian=*/false);
 }