btrfs-progs: mkfs: print the summary

btrfs-progs: mkfs: print the summary

This patch prints the summary of the filesystem after the creation.
The main fileds printed are:
- devices list with their uuid, devid, path and size
- raid profile (dup,single,raid0...)
- leafsize/nodesize/sectorsize
- filesystem features (raid56, extref, mixed-bg)
- chunk size and type

If the '-v' switched is passed, the output is more verbose; if the '-q'
switched is passed, only the errors are printed.

Below an example:

BTRFS filesystem summary:
  Label:                btrfs-test
  UUID:                 14ae8a88-98ac-4f22-8441-79f76ec622f7

  Node size:            4096
  Leaf size:            4096
  Sector size:          4096
  Initial chunks:
    Data+Metadata:      9.01GiB
    System:             18.06MiB
  Metadata profile:     RAID5
  Data profile:         RAID5
  Mixed mode:           YES
  SSD detected:         NO
  Incompat features:    mixed-bg, extref, raid56
  Number of devices:    10
    UUID                                  ID    SIZE    PATH
    ------------------------------------  --  --------- -----------
    df1c7f50-1980-4da2-8bc9-7ee6ffb0b554   1   50.00GiB /dev/vdb
    32c808a0-cd7b-4497-a2c0-1d77a9854af9   2   50.00GiB /dev/vdc
    3159782e-d108-40bc-9e15-090ecac160b4   3   50.00GiB /dev/vdd
    db7eaf0c-beb8-4093-a9d0-b9c25c146305   4   50.00GiB /dev/vde
    c367ca04-1f71-49c0-a331-11fc0b87e9fc   5   50.00GiB /dev/vdf
    e9b73c86-4058-4b3a-90ac-18741a276e70   6   50.00GiB /dev/vdg
    c4298b7a-ad41-4690-bf10-bf748b319413   7   50.00GiB /dev/vdh
    1cf048c8-af8a-4225-b09a-5d12e9b217fa   8    2.00GiB /dev/vdi
    7e157869-768a-4725-bad5-82e6bd05fd17   9    2.00GiB /dev/vdj
    2c9431ac-c7f0-45a5-8529-cef8cf6e4033  10    2.00GiB /dev/vdk

  Total devices size:                         356.01GiB

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
Signed-off-by: David Sterba <dsterba@suse.cz>