btrfs-progs: tune: fix simple quota help string and documentation

The option of "-q" is not working, instead only the longer option is
supported.

And add the missing "--enable-simple-quota" option of man page for
btrfstune.

Reported-by: Anand Jain <[email protected]>
Signed-off-by: Qu Wenruo <[email protected]>

Author: adam900710

Diff for: Documentation/btrfstune.rst

@@ -42,6 +42,13 @@ OPTIONS
 
         Convert to free-space-tree feature (v2 of space cache).
 
+--enable-simple-quota
+	(since kernel 6.7)
+
+	Convert to simple-quota feature. This is an alternative to qgroups
+	with a smaller performance impact but no notion of shared vs. exclusive
+	usage.
+
 -f
         Allow dangerous changes, e.g. clear the seeding flag or change fsid.
         Make sure that you are aware of the dangers.

Diff for: tune/main.c

@@ -103,7 +103,7 @@ static const char * const tune_usage[] = {
 	OPTLINE("-x", "enable skinny metadata extent refs (mkfs: skinny-metadata)"),
 	OPTLINE("-n", "enable no-holes feature (mkfs: no-holes, more efficient sparse file representation)"),
 	OPTLINE("-S <0|1>", "set/unset seeding status of a device"),
-	OPTLINE("-q", "enable simple quotas on the file system. (mkfs: squota)"),
+	OPTLINE("--enable-simple-quota", "enable simple quotas on the file system. (mkfs: squota)"),
 	OPTLINE("--convert-to-block-group-tree", "convert filesystem to track block groups in "
 			"the separate block-group-tree instead of extent tree (sets the incompat bit)"),
 	OPTLINE("--convert-from-block-group-tree",