bcachefs: rename version -> bversion for big endian builds

Builds on big endian systems fail as follows.

fs/bcachefs/bkey.h: In function 'bch2_bkey_format_add_key':
fs/bcachefs/bkey.h:557:41: error:
	'const struct bkey' has no member named 'bversion'

The original commit only renamed the variable for little endian builds.
Rename it for big endian builds as well to fix the problem.

Fixes: cf49f8a ("bcachefs: rename version -> bversion")
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/bcachefs_format.h

@@ -223,7 +223,7 @@ struct bkey {
 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 	struct bpos	p;
 	__u32		size;		/* extent size, in sectors */
-	struct bversion	version;
+	struct bversion	bversion;
 
 	__u8		pad[1];
 #endif