Simplify libtool compatibility hack.

I tested that if I remove "elf" from the message, building a program
that uses libtool prints

checking whether to build shared libraries... no

but with this patch it still prints

checking whether to build shared libraries... yes

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@324428 91177308-0d34-0410-b5e6-96231b3b80d8

Author: espindola

ELF/DriverUtils.cpp

@@ -124,13 +124,7 @@ void elf::printHelp() {
   // in a message for the -help option. If it doesn't match, the scripts
   // assume that the linker doesn't support very basic features such as
   // shared libraries. Therefore, we need to print out at least "elf".
-  // Here, we print out all the targets that we support.
-  outs() << Config->ProgName << ": supported targets: "
-         << "elf32-i386 elf32-iamcu elf32-littlearm elf32-ntradbigmips "
-         << "elf32-ntradlittlemips elf32-powerpc elf32-tradbigmips "
-         << "elf32-tradlittlemips elf32-x86-64 "
-         << "elf64-amdgpu elf64-littleaarch64 elf64-powerpc elf64-tradbigmips "
-         << "elf64-tradlittlemips elf64-x86-64\n";
+  outs() << Config->ProgName << ": supported targets: elf\n";
 }
 
 // Reconstructs command line arguments so that so that you can re-run