bosch_bmp280: reduce i2c array size

Change-Id: I7c4ad178103d80c20c6cd78ec554b51978849b68
diff --git a/firmware/os/drivers/bosch_bmp280/bosch_bmp280.c b/firmware/os/drivers/bosch_bmp280/bosch_bmp280.c
index fbdc97c..ae48996 100644
--- a/firmware/os/drivers/bosch_bmp280/bosch_bmp280.c
+++ b/firmware/os/drivers/bosch_bmp280/bosch_bmp280.c
@@ -47,7 +47,7 @@
 #define BOSCH_BMP280_REG_PRES_MSB       0xf7
 
 #define BOSCH_BMP280_MAX_PENDING_I2C_REQUESTS   4
-#define BOSCH_BMP280_MAX_I2C_TRANSFER_SIZE      24
+#define BOSCH_BMP280_MAX_I2C_TRANSFER_SIZE      6
 
 // This defines how many baro events we could handle being backed up in the
 // queue. Use this to size our slab