[llvm-objdump] properly use c_str() with format("%s").  Improve getLibraryShortNameByIndex() error handling.

llvm-svn: 217930
diff --git a/llvm/test/tools/llvm-objdump/macho-bind.test b/llvm/test/tools/llvm-objdump/macho-bind.test
index 8865a9e..1994465 100644
--- a/llvm/test/tools/llvm-objdump/macho-bind.test
+++ b/llvm/test/tools/llvm-objdump/macho-bind.test
@@ -6,6 +6,6 @@
 # CHECK:__DATA   __data             0x00001028  pointer  0        flat-namespace      _any
 # CHECK:__DATA   __data             0x00001020  pointer  0        main-executable     _fromApp
 # CHECK:__DATA   __data             0x00001018  pointer  0        this-image          _myfunc
-# CHECK:__DATA   __data             0x00001000  pointer  0        libfoo.dylib        _foo
-# CHECK:__DATA   __data             0x00001008  pointer  0        libbar.dylib        _bar
-# CHECK:__DATA   __data             0x00001010  pointer  0        libSystem.B.dylib   _malloc
+# CHECK:__DATA   __data             0x00001000  pointer  0        libfoo              _foo
+# CHECK:__DATA   __data             0x00001008  pointer  0        libbar              _bar
+# CHECK:__DATA   __data             0x00001010  pointer  0        libSystem           _malloc