common/btrfs: rename and enhance _require_btrfs to _require_btrfs_command

Rename _require_btrfs() to _require_btrfs_command() to avoid
confusion, as all other _require_btrfs_* has a quite clear suffix,
like _require_btrfs_mkfs_feature() or _require_btrfs_fs_feature().

Also enhance _require_btrfs_command() to accept 2nd level commands
or options.

Options will be determined by the first "-" char.  This is quite
useful for case like "btrfs inspect-internal dump-tree" and "btrfs
check --qgroup-report".

[eguan: make local vars in _require_btrfs_command "local"]

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

tests/btrfs/004

@@ -51,7 +51,8 @@ _supported_fs btrfs
 _supported_os Linux
 _require_scratch
 _require_no_large_scratch_dev
-_require_btrfs inspect-internal
+_require_btrfs_command inspect-internal logical-resolve
+_require_btrfs_command inspect-internal inode-resolve
 _require_command "/usr/sbin/filefrag" filefrag
 
 rm -f $seqres.full

tests/btrfs/048

@@ -48,7 +48,7 @@ _supported_fs btrfs
 _supported_os Linux
 _require_test
 _require_scratch
-_require_btrfs "property"
+_require_btrfs_command "property"
 
 send_files_dir=$TEST_DIR/btrfs-test-$seq
 

tests/btrfs/059

@@ -51,7 +51,7 @@ _supported_fs btrfs
 _supported_os Linux
 _require_test
 _require_scratch
-_require_btrfs "property"
+_require_btrfs_command "property"
 
 rm -f $seqres.full
 

tests/btrfs/131

@@ -48,7 +48,7 @@ rm -f $seqres.full
 _supported_fs btrfs
 _supported_os Linux
 _require_scratch
-_require_btrfs inspect-internal
+_require_btrfs_command inspect-internal dump-super
 
 mkfs_v1()
 {