ubifs: Default to zstd compression

Compared to lzo and zlib, zstd is the best all-around performer, both in terms
of speed and compression ratio. Set it as the default, if available.

Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/sb.c

@@ -53,6 +53,9 @@
 
 static int get_default_compressor(struct ubifs_info *c)
 {
+	if (ubifs_compr_present(c, UBIFS_COMPR_ZSTD))
+		return UBIFS_COMPR_ZSTD;
+
 	if (ubifs_compr_present(c, UBIFS_COMPR_LZO))
 		return UBIFS_COMPR_LZO;