fix crash issue, since there is getter to make sure it is not null (Lazy…

[KerryJava]

… init), there is no need to keep this line

fix:
#406

[liuxuan30]

Let's hold for a while until we know what happens here causing the crash.

[liuxuan30]

Per the discussion in #406, I think it's better to assign it to a local variable and then assign it to fillFormatter to workaround the crash.

deleting the line is not good, since there is one method being used by line chart renderer->drawCubicFill and drawLinearFill. Once you enable filling, it will crash.

[danielgindi]

This is clearly not a fix, but removing a feature. The problem is in the compiler.