videocrop: fix a memory leak caused by invoking gst_pad_get_peer()
videocrop: fix a memory leak caused by invoking gst_pad_get_peer()

Once is_query_done is set to TRUE, the function exits without decreasing
the reference count of a GstPad instance.
To fix the issue, this patch moves the call to gst_pad_get_peer() (which
increases the GstPad refence count) to after is_query_done is tested.

matsu/gst-plugins-good,matsu/gst-plugins-good,matsu/gst-plugins-good,matsu/gst-plugins-good