Dead code removal

Dead code removal

Removing the redundant setting of format = 32 in the XA_ATOM case.
It was already set to that earlier whe it was assigned actual_format.

xrandr.c:2770:3: warning: Value stored to 'format' is never read
                format=0;
                ^      ~
xrandr.c:2782:7: warning: Value stored to 'format' is never read
                    format = actual_format;
                    ^        ~~~~~~~~~~~~~

Found-by: clang static analyzer
Signed-off-by: Jeremy Huddleston <jeremyhu@apple.com>