gdc: reset alloc flag when free dma buffer [2/2]

PD#SWPL-4354

Problem:
alloc flag is not correct when free dma buffer

Solution:
reset alloc flag when free dma buffer

Verify:
test pass on g12a-u200

Change-Id: Idfc0be5b394d18799232f6239b3f6c6df9181ce0
Signed-off-by: Jian Cao <jian.cao@amlogic.com>

drivers/amlogic/media/gdc/app/gdc_dmabuf.c

@@ -418,6 +418,7 @@ int gdc_dma_buffer_free(struct aml_dma_buffer *buffer, int index)
 		return (-EINVAL);
 	}
 	aml_dma_put(buf);
+	buffer->gd_buffer[index].alloc = 0;
 	return 0;
 }