add trivial check for return code, fixes CID1261778
add trivial check for return code, fixes CID1261778

ShengYenPeng/libchewing,yan12125/libchewing,robert501128/libchewing,PingNote/libchewing,bbyykk/libtaigi,cwlin/libchewing,kito-cheng/libchewing,PeterDaveHello/libchewing,Chocobo1/libchewing,yan12125/libchewing,PingNote/libchewing,Chocobo1/libchewing,bbyykk/libtaigi,chewing/libchewing,simonfork/libchewing,bbyykk/libtaigi,cwlin/libchewing,yan12125/libchewing,mangokingTW/libchewing,chewing/libchewing,simonfork/libchewing,kito-cheng/libchewing,ShengYenPeng/libchewing,cwlin/libchewing,cwlin/libchewing,dimotsai/libchewing,hiunnhue/libchewing,robert501128/libchewing,PeterDaveHello/libchewing,PeterDaveHello/libchewing,hiunnhue/libchewing,kito-cheng/libchewing,hiunnhue/libchewing,mangokingTW/libchewing,bbyykk/libtaigi,simonfork/libchewing,cwlin/libchewing,dimotsai/libchewing,chewing/libchewing,Chocobo1/libchewing,mangokingTW/libchewing,yan12125/libchewing,PingNote/libchewing,PingNote/libchewing,ShengYenPeng/libchewing,PeterDaveHello/libchewing,kito-cheng/libchewing,mangokingTW/libchewing,Chocobo1/libchewing,hiunnhue/libchewing,ShengYenPeng/libchewing,dimotsai/libchewing,Chocobo1/libchewing,hiunnhue/libchewing,bbyykk/libtaigi,chewing/libchewing,simonfork/libchewing,robert501128/libchewing,robert501128/libchewing,dimotsai/libchewing