iio:pressure:mpl3115: Fix sparse cast to restricted __be32 warning

>> >> drivers/iio/pressure/mpl3115.c:101:46: sparse: cast to restricted __be32
>> >> drivers/iio/pressure/mpl3115.c:115:46: sparse: cast to restricted __be32

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/pressure/mpl3115.c b/drivers/iio/pressure/mpl3115.c
index ac8c8ab..ba6d0c5 100644
--- a/drivers/iio/pressure/mpl3115.c
+++ b/drivers/iio/pressure/mpl3115.c
@@ -77,7 +77,7 @@
 			    int *val, int *val2, long mask)
 {
 	struct mpl3115_data *data = iio_priv(indio_dev);
-	s32 tmp = 0;
+	__be32 tmp = 0;
 	int ret;
 
 	switch (mask) {