No real changes, just slightly simplify wxSVGFileDCImpl code.

Move m_graphics_changed check inside NewGraphics() itself instead of checking
whether it's true each time before calling it, it is better to both test the
flag and reset it inside this function rather than do the first part in the
caller and the second one in the callee.

Also rename the function to NewGraphicsIfNeeded() to make its meaning more
clear.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72493 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775