narrow write-seek-write's flags to only use O_RDWR | O_CREAT
narrow write-seek-write's flags to only use O_RDWR | O_CREAT

It was enabling unecessary flags (e.g., O_APPEND)

guardianproject/libsqlfs,guardianproject/libsqlfs,guardianproject/libsqlfs,spthaolt/libsqlfs,guardianproject/libsqlfs,eighthave/libsqlfs,spthaolt/libsqlfs,eighthave/libsqlfs,spthaolt/libsqlfs,spthaolt/libsqlfs,eighthave/libsqlfs,eighthave/libsqlfs,spthaolt/libsqlfs,eighthave/libsqlfs,guardianproject/libsqlfs