style: cppcheck cleanup

[command/guid.cpp:37]: (style) The scope of the variable 'rc' can be
reduced.
[socket_channel.hpp:44]: (performance) Variable 'timeout' is assigned
in constructor body. Consider performing initialization in
initialization list.
[sd_event_loop.cpp:107]: (style) The scope of the variable 'instance'
can be reduced.
[sd_event_loop.cpp:108]: (style) The scope of the variable 'rc' can be
reduced.
[sd_event_loop.cpp:142]: (style) The scope of the variable 'instance'
can be reduced.
[sd_event_loop.cpp:304]: (style) The scope of the variable 'rc' can be
reduced.

Change-Id: Id090cb217ea7ed9019f1b8d39ebebd6bb73113b1
Signed-off-by: Patrick Venture <venture@google.com>
3 files changed