btrfs-progs: move dir-item.c to kernel-shared/

Signed-off-by: David Sterba <dsterba@suse.com>

Makefile

@@ -143,7 +143,7 @@ CHECKER_FLAGS := -include $(check_defs) -D__CHECKER__ \
 	-D__CHECK_ENDIAN__ -Wbitwise -Wuninitialized -Wshadow -Wundef \
 	-U_FORTIFY_SOURCE -Wdeclaration-after-statement -Wdefault-bitfield-sign
 
-objects = dir-item.o inode-map.o \
+objects = kernel-shared/dir-item.o inode-map.o \
 	  qgroup.o kernel-lib/list_sort.o props.o \
 	  kernel-shared/ulist.o check/qgroup-verify.o kernel-shared/backref.o \
 	  common/string-table.o common/task-utils.o \