staging: iio: meter: remove unused variable

This patch removes a variable that was simply used to
store the return value of a function call before
returning it.

The issue was detected and resolved using the following
coccinelle script:

@@
identifier len,f;
@@

-int len;
 ... when != len
     when strict
-len =
+return
        f(...);
-return len;

Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/meter/ade7759.c

@@ -215,18 +215,15 @@ error_ret:
 
 static int ade7759_reset(struct device *dev)
 {
-	int ret;
 	u16 val;
 
 	ade7759_spi_read_reg_16(dev,
 			ADE7759_MODE,
 			&val);
 	val |= 1 << 6; /* Software Chip Reset */
-	ret = ade7759_spi_write_reg_16(dev,
+	return ade7759_spi_write_reg_16(dev,
 			ADE7759_MODE,
 			val);
-
-	return ret;
 }
 
 static IIO_DEV_ATTR_AENERGY(ade7759_read_40bit, ADE7759_AENERGY);