DolphinWX: Fix scrolling in hex mode for the memory view

Prior to this after painting the hex values, it would increment the curAddress by 32. This is not only a bug, but unnecessary, since the OnMouseDownL and OnScrollWheel functions should be the only things to handle address incrementing for scrolling purposes.
Merge pull request #768 from lioncash/hex-view

DolphinWX: Fix scrolling in hex mode for the memory view