pspp-sheet-view: Remove write-only variable from pspp_sheet_view_draw_bin().
[pspp] / src /
drwxr-xr-x   ..
-rw-r--r-- 21 .gitignore
-rw-r--r-- 921 automake.mk
drwxr-xr-x - data
drwxr-xr-x - language
drwxr-xr-x - libpspp
drwxr-xr-x - math
drwxr-xr-x - output
drwxr-xr-x - ui