nvme: Fix error when passthru does not match opcode based flags

nvme: Fix error when passthru does not match opcode based flags

when write option is set(but opcode is not), file should open with read flag
same for read
it occur 'Bad file descriptor' error when access the file

write & read flags are set by opcode as well
Spec mentioned below about opcode(01:00 Data Transfer)
All options to the command shall transfer data as specified or transfer no data.
All commands, including vendor specific commands
01b = host to controller; 10b = controller to host

Reported-by: Kyungsik Shin <ks1012.shin@samsung.com>
Signed-off-by: Steven Seungcheol Lee <sc108.lee@samsung.com>