iio: chemical: sps30: remove printk format specifier

pr_fmt is used by printk wrappers. There are not any in the driver
code so remove the format specifier.
Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/chemical/sps30.c

@@ -7,8 +7,6 @@
  * I2C slave address: 0x69
  */
 
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
 #include <asm/unaligned.h>
 #include <linux/crc8.h>
 #include <linux/delay.h>