UPSTREAM: charsets: set error if UTF-8 validation fails

Otherwise, mm_modem_charset_bytearray_to_utf8() may return NULL
without error set, and that will trigger a crash in the caller.

Fixes https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/511

(cherry picked from commit 27f6679aa87b7b4a7b214d3f08f83bec16434580)

BUG=b:218395230
TEST=None

Change-Id: I7d80e8efe0d5e9224e0449a557470fc0e1416e1d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/modemmanager-next/+/3472884
Tested-by: Andrew Lassalle <andrewlassalle@chromium.org>
Auto-Submit: Andrew Lassalle <andrewlassalle@chromium.org>
Reviewed-by: Madhav <madhavadas@google.com>
Commit-Queue: Andrew Lassalle <andrewlassalle@chromium.org>
(cherry picked from commit db1ff845c33bfa21694e2009b314efa4282eae51)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/modemmanager-next/+/3481948
Reviewed-by: Nagi Marupaka <nmarupaka@google.com>
Commit-Queue: Nagi Marupaka <nmarupaka@google.com>
1 file changed