smb3: add trace event for mknod

Add trace points to help debug mknod and mkfifo:

   smb3_mknod_done
   smb3_mknod_enter
   smb3_mknod_err

Example output:

      TASK-PID     CPU#  |||||  TIMESTAMP  FUNCTION
         | |         |   |||||     |         |
    mkfifo-6163    [003] .....   960.425558: smb3_mknod_enter: xid=12 sid=0xb55130f6 tid=0x46e6241c path=\fifo1
    mkfifo-6163    [003] .....   960.432719: smb3_mknod_done: xid=12 sid=0xb55130f6 tid=0x46e6241c

Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Reviewed-by: Meetakshi Setiya <msetiya@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>