git: fix leaking system paths

Git has some flags to make it output system paths as they have been
compiled into Git. This is done by calling `system_path()`, which
returns an allocated string. This string isn't ever free'd though,
creating a memory leak.

Plug those leaks. While they are surfaced by t0211, there are more
memory leaks looming exposed by that test suite and it thus does not yet
pass with the memory leak checker enabled.

Helped-by: Taylor Blau <[email protected]>
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

git.c

@@ -143,6 +143,13 @@ void setup_auto_pager(const char *cmd, int def)
 	commit_pager_choice();
 }
 
+static void print_system_path(const char *path)
+{
+	char *s_path = system_path(path);
+	puts(s_path);
+	free(s_path);
+}
+
 static int handle_options(const char ***argv, int *argc, int *envchanged)
 {
 	const char **orig_argv = *argv;
@@ -173,15 +180,15 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 				exit(0);
 			}
 		} else if (!strcmp(cmd, "--html-path")) {
-			puts(system_path(GIT_HTML_PATH));
+			print_system_path(GIT_HTML_PATH);
 			trace2_cmd_name("_query_");
 			exit(0);
 		} else if (!strcmp(cmd, "--man-path")) {
-			puts(system_path(GIT_MAN_PATH));
+			print_system_path(GIT_MAN_PATH);
 			trace2_cmd_name("_query_");
 			exit(0);
 		} else if (!strcmp(cmd, "--info-path")) {
-			puts(system_path(GIT_INFO_PATH));
+			print_system_path(GIT_INFO_PATH);
 			trace2_cmd_name("_query_");
 			exit(0);
 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {