btrfs-progs: build: generate all dependency files

btrfs-progs: build: generate all dependency files

We're missing several dependency files like:

$ diff -u <(find -name '*.o'|cut -d. -f2|sort) <(find -name '*.o.d'|cut -d. -f2|sort)
@@ -3,7 +3,6 @@
 /btrfs-corrupt-block
 /btrfs-debug-tree
 /btrfs-find-root
-/btrfs-list
 /btrfs-map-logical
 /btrfs-select-super
 /btrfstune
@@ -29,11 +28,6 @@
 /cmds-scrub
 /cmds-send
 /cmds-subvolume
-/convert/common
-/convert/main
-/convert/source-ext2
-/convert/source-fs
-/convert/source-reiserfs
 /ctree
 /dir-item
 /disk-io
<snip>

This is due to moving things out of objects and cmds_objects variables. Such
missing dependency files cause mis-building of some source files (try touch
utils.h; make mkfs/main.o).

This patch introduce a new variable "all_objects" to keep all the objects and
use the variable to generate proper dependency file building rules.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>