Revert "gpiolib: annotate gpio-intialization with __must_check"

This reverts commit 0fdae42d361bbb431ca0ab0efed5126a94821177, which
wasn't really supposed to go in, and causes lots of annoying warnings.

Quoth Andrew:
  "Complete brainfart - I meant to drop that patch ages ago."

Quoth Greg:
  "Ick, yeah, that patch isn't ok to go in as-is, all of the callers
   need to be fixed up first, which is what I thought we had agreed on..."

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/gpio.txt

@@ -135,7 +135,7 @@ setting up a platform_device using the GPIO, is mark its direction:
 	int gpio_direction_input(unsigned gpio);
 	int gpio_direction_output(unsigned gpio, int value);
 
-The return value is zero for success, else a negative errno.  It must
+The return value is zero for success, else a negative errno.  It should
 be checked, since the get/set calls don't have error returns and since
 misconfiguration is possible.  You should normally issue these calls from
 a task context.  However, for spinlock-safe GPIOs it's OK to use them

include/asm-generic/gpio.h

@@ -147,11 +147,11 @@ extern struct gpio_chip *gpiochip_find(void *data,
 /* Always use the library code for GPIO management calls,
  * or when sleeping may be involved.
  */
-extern int __must_check gpio_request(unsigned gpio, const char *label);
+extern int gpio_request(unsigned gpio, const char *label);
 extern void gpio_free(unsigned gpio);
 
-extern int __must_check gpio_direction_input(unsigned gpio);
-extern int __must_check gpio_direction_output(unsigned gpio, int value);
+extern int gpio_direction_input(unsigned gpio);
+extern int gpio_direction_output(unsigned gpio, int value);
 
 extern int gpio_set_debounce(unsigned gpio, unsigned debounce);
 
@@ -192,8 +192,8 @@ struct gpio {
 	const char	*label;
 };
 
-extern int __must_check gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
-extern int __must_check gpio_request_array(struct gpio *array, size_t num);
+extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
+extern int gpio_request_array(struct gpio *array, size_t num);
 extern void gpio_free_array(struct gpio *array, size_t num);
 
 #ifdef CONFIG_GPIO_SYSFS

include/linux/gpio.h

@@ -30,7 +30,7 @@ static inline int gpio_is_valid(int number)
 	return 0;
 }
 
-static inline int __must_check gpio_request(unsigned gpio, const char *label)
+static inline int gpio_request(unsigned gpio, const char *label)
 {
 	return -ENOSYS;
 }
@@ -62,12 +62,12 @@ static inline void gpio_free_array(struct gpio *array, size_t num)
 	WARN_ON(1);
 }
 
-static inline int __must_check gpio_direction_input(unsigned gpio)
+static inline int gpio_direction_input(unsigned gpio)
 {
 	return -ENOSYS;
 }
 
-static inline int __must_check gpio_direction_output(unsigned gpio, int value)
+static inline int gpio_direction_output(unsigned gpio, int value)
 {
 	return -ENOSYS;
 }