w1: ds2438: make several functions static

The functions w1_ds2438_get_page, w1_ds2438_get_temperature,
w1_ds2438_change_config_bit and w1_ds2438_get_voltage are local to
the source and do not need to be in global scope, so make it static.

Cleans up sparse warnings:
symbol 'w1_ds2438_get_page' was not declared. Should it be static?
symbol 'w1_ds2438_get_temperature' was not declared. Should it be static?
symbol 'w1_ds2438_change_config_bit' was not declared. Should it be static?
symbol 'w1_ds2438_get_voltage' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/w1/slaves/w1_ds2438.c

@@ -51,7 +51,7 @@
 #define DS2438_CURRENT_MSB		0x06
 #define DS2438_THRESHOLD		0x07
 
-int w1_ds2438_get_page(struct w1_slave *sl, int pageno, u8 *buf)
+static int w1_ds2438_get_page(struct w1_slave *sl, int pageno, u8 *buf)
 {
 	unsigned int retries = W1_DS2438_RETRIES;
 	u8 w1_buf[2];
@@ -85,7 +85,7 @@ int w1_ds2438_get_page(struct w1_slave *sl, int pageno, u8 *buf)
 	return -1;
 }
 
-int w1_ds2438_get_temperature(struct w1_slave *sl, int16_t *temperature)
+static int w1_ds2438_get_temperature(struct w1_slave *sl, int16_t *temperature)
 {
 	unsigned int retries = W1_DS2438_RETRIES;
 	u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/];
@@ -127,7 +127,7 @@ int w1_ds2438_get_temperature(struct w1_slave *sl, int16_t *temperature)
 	return ret;
 }
 
-int w1_ds2438_change_config_bit(struct w1_slave *sl, u8 mask, u8 value)
+static int w1_ds2438_change_config_bit(struct w1_slave *sl, u8 mask, u8 value)
 {
 	unsigned int retries = W1_DS2438_RETRIES;
 	u8 w1_buf[3];
@@ -186,7 +186,8 @@ int w1_ds2438_change_config_bit(struct w1_slave *sl, u8 mask, u8 value)
 	return -1;
 }
 
-uint16_t w1_ds2438_get_voltage(struct w1_slave *sl, int adc_input, uint16_t *voltage)
+static uint16_t w1_ds2438_get_voltage(struct w1_slave *sl,
+				      int adc_input, uint16_t *voltage)
 {
 	unsigned int retries = W1_DS2438_RETRIES;
 	u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/];