os2: fix leak and always close directory

core/os/os2/internal_util.odin

@@ -76,7 +76,7 @@ concatenate :: proc(strings: []string, allocator: runtime.Allocator) -> (res: st
 	for s in strings {
 		n += len(s)
 	}
-	buf := make([]byte, n) or_return
+	buf := make([]byte, n, allocator) or_return
 	n = 0
 	for s in strings {
 		n += copy(buf[n:], s)

core/os/os2/path_posix.odin

@@ -61,6 +61,7 @@ _remove_all :: proc(path: string) -> Error {
 	if dir == nil {
 		return _get_platform_error()
 	}
+	defer posix.closedir(dir)
 
 	for {
 		posix.set_errno(.NONE)
@@ -91,7 +92,6 @@ _remove_all :: proc(path: string) -> Error {
 	if posix.rmdir(cpath) != .OK {
 		return _get_platform_error()
 	}
-	posix.closedir(dir)
 	return nil
 }