Eliminate all gcc/cobol dependencies on <err.h>

gcc/cobol/ChangeLog

gcc/cobol/cdf-copy.cc

gcc/cobol/cdf_text.h

gcc/cobol/charmaps-copy.cc

gcc/cobol/copybook.h

gcc/cobol/dts.h

gcc/cobol/genapi.cc

gcc/cobol/lexio.cc

gcc/cobol/lexio.h

gcc/cobol/parse.y

gcc/cobol/parse_ante.h

gcc/cobol/scan.l

gcc/cobol/scan_ante.h

gcc/cobol/symbols.cc

gcc/cobol/symbols.h

gcc/cobol/symfind.cc

gcc/cobol/util.cc

libgcobol/charmaps.cc

libgcobol/constants.cc

libgcobol/gmath.cc