Remove erroneous null termination

The std::string is created using char pointer _and_ buffer size, so
null termination wasn't necessary in there (might even be problematic
with other tools which aren't strictly text based).

CC #35.

src/core/elf.cpp

@@ -163,7 +163,6 @@ namespace linuxdeploy {
                         auto outBufSize = outBuf.size();
                         outBuf.reserve(outBufSize + size + 1);
                         std::copy(buf.begin(), buf.begin() + size, std::back_inserter(outBuf));
-                        outBuf.push_back('\0');
                     }
                 } while (lddProc.poll() < 0);