dpkg-divert: rename involves overwriting `/usr/X11R6/lib/libGL.so.1' with
  different file `/usr/X11R6/lib/fglrx/libGL.so.1.xlibmesa', not allowed
dpkg: error processing xorg-driver-fglrx (--remove):
 subprocess post-removal script returned error exit status 2
Errors were encountered while processing:
 xorg-driver-fglrx
E: Sub-process /usr/bin/dpkg returned an error code (1)