tools: bpftool: alias show and list commands

iproute2 seems to accept show and list as aliases.
Let's do the same thing, and by allowing both bring
cgroup syntax back in line with maps and progs.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/bpf/bpftool/Documentation/bpftool-cgroup.rst

@@ -15,12 +15,12 @@ SYNOPSIS
 	*OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-f** | **--bpffs** } }
 
 	*COMMANDS* :=
-	{ **list** | **attach** | **detach** | **help** }
+	{ **show** | **list** | **attach** | **detach** | **help** }
 
 MAP COMMANDS
 =============
 
-|	**bpftool** **cgroup list** *CGROUP*
+|	**bpftool** **cgroup { show | list }** *CGROUP*
 |	**bpftool** **cgroup attach** *CGROUP* *ATTACH_TYPE* *PROG* [*ATTACH_FLAGS*]
 |	**bpftool** **cgroup detach** *CGROUP* *ATTACH_TYPE* *PROG*
 |	**bpftool** **cgroup help**
@@ -31,7 +31,7 @@ MAP COMMANDS
 
 DESCRIPTION
 ===========
-	**bpftool cgroup list** *CGROUP*
+	**bpftool cgroup { show | list }** *CGROUP*
 		  List all programs attached to the cgroup *CGROUP*.
 
 		  Output will start with program ID followed by attach type,