xfs: Remove unused function is_rt_data_fork

The function are defined in the rmap_repair.c file, but not called
elsewhere, so delete the unused function.

fs/xfs/scrub/rmap_repair.c:436:1: warning: unused function 'is_rt_data_fork'.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=8425Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

fs/xfs/scrub/rmap_repair.c

@@ -432,14 +432,6 @@ xrep_rmap_scan_iroot_btree(
 	return error;
 }
 
-static inline bool
-is_rt_data_fork(
-	struct xfs_inode	*ip,
-	int			whichfork)
-{
-	return XFS_IS_REALTIME_INODE(ip) && whichfork == XFS_DATA_FORK;
-}
-
 /*
  * Iterate the block mapping btree to collect rmap records for anything in this
  * fork that matches the AG.  Sets @mappings_done to true if we've scanned the