Add -v and -o switches

Add -v and -o switches to the mkfs.btrfs man page.

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>

Documentation/mkfs.btrfs.txt

@@ -17,13 +17,16 @@ $$[-l|--leafsize <leafsize>]$$
 $$[-L|--label <label>]$$
 $$[-m|--metadata <metadata profile>]$$
 $$[-M|--mixed]$$
+$$[-q|--quiet]$$
 $$[-s|--sectorsize <sectorsize>]$$
 $$[-r|--rootdir <rootdir>]$$
 $$[-K|--nodiscard]$$
 $$[-O|--features <feature1>[,<feature2>...]]$$
+$$[-q|--quiet]$$
 $$[-U|--uuid <UUID>]$$
 $$[-h]$$
 $$[-V|--version]$$
+$$[-v|--verbose]$$
 $$<device> [<device>...]$$
 
 DESCRIPTION
@@ -120,6 +123,12 @@ the system.
 -V|--version::
 Print the *mkfs.btrfs* version and exit.
 
+-v|--verbose::
+Increase the verbosity of the command.
+
+-q|--quiet::
+Print only the errors.
+
 -h::
 Print help.