media: staging/intel-ipu3: Fix set_fmt error handling

If there in an error during a set_fmt, do not overwrite the previous
sizes with the invalid config.

Without this patch, v4l2-compliance ends up allocating 4GiB of RAM and
causing the following OOPs

[   38.662975] ipu3-imgu 0000:00:05.0: swiotlb buffer is full (sz: 4096 bytes)
[   38.662980] DMA: Out of SW-IOMMU space for 4096 bytes at device 0000:00:05.0
[   38.663010] general protection fault: 0000 [#1] PREEMPT SMP

Cc: stable@vger.kernel.org
Fixes: 6d5f26f2 ("media: staging/intel-ipu3-v4l: reduce kernel stack usage")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>