tools: bpftool: add bash completion for CFG dump

Add bash completion for the "visual" keyword used for dumping the CFG of
eBPF programs with bpftool. Make sure we only complete with this keyword
when we dump "xlated" (and not "jited") instructions.
Acked-by: NJiong Wang <jiong.wang@netronome.com>
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

tools/bpf/bpftool/bash-completion/bpftool

@@ -147,7 +147,7 @@ _bpftool()
 
     # Deal with simplest keywords
     case $prev in
-        help|key|opcodes)
+        help|key|opcodes|visual)
             return 0
             ;;
         tag)
@@ -223,11 +223,16 @@ _bpftool()
                             return 0
                             ;;
                     *)
-                            _bpftool_once_attr 'file'
+                        _bpftool_once_attr 'file'
+                        if _bpftool_search_list 'xlated'; then
+                            COMPREPLY+=( $( compgen -W 'opcodes visual' -- \
+                                "$cur" ) )
+                        else
                             COMPREPLY+=( $( compgen -W 'opcodes' -- \
                                 "$cur" ) )
-                            return 0
-                            ;;
+                        fi
+                        return 0
+                        ;;
                     esac
                     ;;
                 pin)