entity: simplify mpd_get_next_pair() calls
entity: simplify mpd_get_next_pair() calls

Call mpd_get_next_pair() only once in the "while" condition.

cmende/libmpdclient,jwise/libmpdclient,psych0tik/libmpdclient2,cmende/libmpdclient,psych0tik/libmpdclient2,sl0th/libmpdclient,cmende/libmpdclient,sl0th/libmpdclient,jwise/libmpdclient,OpenInkpot-archive/iplinux-libmpdclient,jagleeso/libmpdclient,sl0th/libmpdclient,jagleeso/libmpdclient,OpenInkpot-archive/iplinux-libmpdclient,yusiwen/libmpdclient,yusiwen/libmpdclient,jagleeso/libmpdclient,jwise/libmpdclient,yusiwen/libmpdclient