bcachefs: remove the unused parameter in macro bkey_crc_next

In the macro definition of bkey_crc_next, five parameters
were accepted, but only four of them were used. Let's remove
the unused one.

The patch has only passed compilation tests, but it should be fine.
Signed-off-by: Julian Sun <sunjunchao2870@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/extents.h

@@ -357,7 +357,7 @@ out:									\
 	__bkey_for_each_ptr_decode(_k, (_p).start, (_p).end,		\
 				   _ptr, _entry)
 
-#define bkey_crc_next(_k, _start, _end, _crc, _iter)			\
+#define bkey_crc_next(_k, _end, _crc, _iter)			\
 ({									\
 	__bkey_extent_entry_for_each_from(_iter, _end, _iter)		\
 		if (extent_entry_is_crc(_iter)) {			\
@@ -372,7 +372,7 @@ out:									\
 #define __bkey_for_each_crc(_k, _start, _end, _crc, _iter)		\
 	for ((_crc) = bch2_extent_crc_unpack(_k, NULL),			\
 	     (_iter) = (_start);					\
-	     bkey_crc_next(_k, _start, _end, _crc, _iter);		\
+	     bkey_crc_next(_k, _end, _crc, _iter);		\
 	     (_iter) = extent_entry_next(_iter))
 
 #define bkey_for_each_crc(_k, _p, _crc, _iter)				\