Attempt to free stdout memory

zig/sdl/hello_sdl.zig

@@ -64,7 +64,7 @@ pub fn main() !void {
    var pos: usize = 0;
    var max_chars = std.math.min(@divTrunc(@intCast(usize, window_width), @intCast(usize, glyph_width)), msg.len);
    var result: []const u8 = "";
    var result: []const u8 = try gpa.alloc(u8, 0);
    const keyboardState = c.SDL_GetKeyboardState(null);
@@ -115,6 +115,7 @@ pub fn main() !void {
                                msg[pos] = '_';
                            },
                            c.SDLK_RETURN => {
                                gpa.free(result);
                                result = try runCommand(&msg, gpa);
                                var i: usize = 0;
                                while (i < max_chars) : (i += 1) {
@@ -170,6 +171,8 @@ pub fn main() !void {
        c.SDL_Delay(16);
    }
    _ = general_purpose_allocator.detectLeaks();
}
fn runCommand(raw_cmd: []const u8, allocator: *std.mem.Allocator) ![]const u8 {