completion: use __git when calling --list-cmds

As we made --list-cmds read the local configuration file in an
earlier step, the completion.commands variable respects repo-level
configuration.  Use __git which ensures that the proper repo config
is consulted if the command line contains 'git -C /some/other/repo'.

Suggested-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -1024,7 +1024,7 @@ __git_all_commands=
 __git_compute_all_commands ()
 {
 	test -n "$__git_all_commands" ||
-	__git_all_commands=$(git --list-cmds=main,others,alias,nohelpers)
+	__git_all_commands=$(__git --list-cmds=main,others,alias,nohelpers)
 }
 
 # Lists all set config variables starting with the given section prefix,
@@ -1652,9 +1652,9 @@ _git_help ()
 	esac
 	if test -n "$GIT_TESTING_ALL_COMMAND_LIST"
 	then
-		__gitcomp "$GIT_TESTING_ALL_COMMAND_LIST $(git --list-cmds=alias,list-guide) gitk"
+		__gitcomp "$GIT_TESTING_ALL_COMMAND_LIST $(__git --list-cmds=alias,list-guide) gitk"
 	else
-		__gitcomp "$(git --list-cmds=main,nohelpers,alias,list-guide) gitk"
+		__gitcomp "$(__git --list-cmds=main,nohelpers,alias,list-guide) gitk"
 	fi
 }
 
@@ -2925,7 +2925,7 @@ __git_main ()
 			then
 				__gitcomp "$GIT_TESTING_PORCELAIN_COMMAND_LIST"
 			else
-				__gitcomp "$(git --list-cmds=list-mainporcelain,others,nohelpers,alias,list-complete,config)"
+				__gitcomp "$(__git --list-cmds=list-mainporcelain,others,nohelpers,alias,list-complete,config)"
 			fi
 			;;
 		esac