spi: dln2: Fix reference leak to master

spi: dln2: Fix reference leak to master

Call spi_master_get() holds the reference count to master device, thus
we need an additional spi_master_put() call to reduce the reference
count, otherwise we will leak a reference to master.

This commit fix it by removing the unnecessary spi_master_get().

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20210409082955.2907950-1-weiyongjun1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>