tif_fax3.h: check for buffer overflow in EXPAND2D before "calling" CLEANUP_RUNS()
fixes #179 (closed)
this fixes the regression introduced in 02bb0175 / 72c4acef ( merge request !110 (merged) )
It may be a better fix to do the overflow check in SETVALUE() but the macro do { } while(0) construct makes it difficult to quit the loop properly.