gcc4 on 64bit warnings on compiling nsd 2.3.1

NSD
1

zlexer.c: In function 'yylex':
zlexer.lex:267: warning: ignoring return value of 'fwrite', declared with attribute warn_unused_result

zonec.c: In function 'zparser_conv_loc':
zonec.c:672: warning: ignoring return value of 'strtol', declared with attribute warn_unused_result

nsd-xfer.c: In function 'print_rr':
nsd-xfer.c:459: warning: ignoring return value of 'fwrite', declared with attribute warn_unused_result

Paul