max_seg_size is unsigned int and it can have a value up to 2^32
(for eg:-RZ_DMAC driver sets dma_set_max_seg_size as U32_MAX)
When this value is used in min_t() as an integer type, it becomes
-1 and the value of sgs becomes 0.
Fix this issue by replacing the 'int' data type with 'unsigned int'
in min_t().