Another unreachable code issue.

[QiAnXinCodeSafe]

Hi all,

This is Qihoo360 CodeSafe Team, we found a unreachable code issue at

twister-core/libtorrent/src/utp_stream.cpp

Line 788 in 53ffd95

if (!m_impl) return;

. m_impl is guaranteed to be false at line 788 because the null-check at the start of the close(). Please confirm it!

Thanks in advance!.

Qihoo360 CodeSafe Team.