xfs: remove boilerplate around xfs_btree_init_block

Now that xfs_btree_init_block_int is able to determine crc
status from the passed-in mp, we can determine the proper
magic as well if we are given a btree number, rather than
an explicit magic value.

Change xfs_btree_init_block[_int] callers to pass in the
btree number, and let xfs_btree_init_block_int use the
xfs_magics array via the xfs_btree_magic macro to determine
which magic value is needed.  This makes all of the
if (crc) / else stanzas identical, and the if/else can be
removed, leading to a single, common init_block call.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index a80bf80..f93072b 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -71,15 +71,9 @@ xfs_bmdr_to_bmbt(
 	xfs_bmbt_key_t		*tkp;
 	__be64			*tpp;
 
-	if (xfs_sb_version_hascrc(&mp->m_sb))
-		xfs_btree_init_block_int(mp, rblock, XFS_BUF_DADDR_NULL,
-				 XFS_BMAP_CRC_MAGIC, 0, 0, ip->i_ino,
+	xfs_btree_init_block_int(mp, rblock, XFS_BUF_DADDR_NULL,
+				 XFS_BTNUM_BMAP, 0, 0, ip->i_ino,
 				 XFS_BTREE_LONG_PTRS);
-	else
-		xfs_btree_init_block_int(mp, rblock, XFS_BUF_DADDR_NULL,
-				 XFS_BMAP_MAGIC, 0, 0, ip->i_ino,
-				 XFS_BTREE_LONG_PTRS);
-
 	rblock->bb_level = dblock->bb_level;
 	ASSERT(be16_to_cpu(rblock->bb_level) > 0);
 	rblock->bb_numrecs = dblock->bb_numrecs;