eeprom: idt_89hpesx: remove redundant variable csrval_len

Variable csrval_len is being assigned but is never used hence it is
redundant and can be removed.

Cleans up clang warning:
warning: variable 'csrval_len' set but not used [-Wunused-but-set-variable]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/eeprom/idt_89hpesx.c

@@ -938,7 +938,7 @@ static ssize_t idt_dbgfs_csr_write(struct file *filep, const char __user *ubuf,
 {
 	struct idt_89hpesx_dev *pdev = filep->private_data;
 	char *colon_ch, *csraddr_str, *csrval_str;
-	int ret, csraddr_len, csrval_len;
+	int ret, csraddr_len;
 	u32 csraddr, csrval;
 	char *buf;
 
@@ -974,12 +974,10 @@ static ssize_t idt_dbgfs_csr_write(struct file *filep, const char __user *ubuf,
 		csraddr_str[csraddr_len] = '\0';
 		/* Register value must follow the colon */
 		csrval_str = colon_ch + 1;
-		csrval_len = strnlen(csrval_str, count - csraddr_len);
 	} else /* if (str_colon == NULL) */ {
 		csraddr_str = (char *)buf; /* Just to shut warning up */
 		csraddr_len = strnlen(csraddr_str, count);
 		csrval_str = NULL;
-		csrval_len = 0;
 	}
 
 	/* Convert CSR address to u32 value */