posix: Split on ":" in path d:\export makes minio use wrong disk. (#3027)
posix: Split on ":" in path d:\export makes minio use wrong disk. (#3027)

As the host/path split happens at a higher layer now, split at posix is not needed.
fixes part of #2987
NitishT/minio,harshavardhana/minio,krisis/minio,aead/minio,vadmeste/minio,luomeiqin/minio,harshavardhana/minio,abperiasamy/minio,fwessels/minio,jimjag/minio,alexellis/minio,donatello/minio,aead/minio,fwessels/minio,minio/minio,abperiasamy/minio,harshavardhana/minio,koolhead17/minio,brendanashworth/minio,luomeiqin/minio,brendanashworth/minio,minio/minio,brendanashworth/minio,krishnasrinivas/minio,aead/minio,jimjag/minio,harshavardhana/minio,rushenn/minio,krishnasrinivas/minio,brendanashworth/minio,balamurugana/minio,alexellis/minio,hackintoshrao/minio,aead/minio,vadmeste/minio,dutchcoders/minio,harshavardhana/minio,jimjag/minio,dvstate/minio,krishnasrinivas/minio,aead/minio,donatello/minio,harshavardhana/minio,fwessels/minio,krisis/minio,aead/minio,harshavardhana/minio,aead/minio,NitishT/minio,abperiasamy/minio,NitishT/minio,harshavardhana/minio,hackintoshrao/minio,luomeiqin/minio,dvstate/minio,aead/minio,hackintoshrao/minio,rushenn/minio,abperiasamy/minio,balamurugana/minio,fwessels/minio,jimjag/minio,krishnasrinivas/minio,rushenn/minio,NitishT/minio,dutchcoders/minio,rushenn/minio,dutchcoders/minio,dvstate/minio,koolhead17/minio,hackintoshrao/minio,dvstate/minio,luomeiqin/minio,dutchcoders/minio