usb: gadget: Use kstrtobool() instead of strtobool()

strtobool() is the same as kstrtobool().
However, the latter is more used within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

While at it, include the corresponding header file (<linux/kstrtox.h>)

Signed-off-by: Christophe JAILLET <[e-mail]>
Link: https://lore.kernel.org/r/09bc980d84[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/gadget/configfs.c

···
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <linux/kstrtox.h>
 #include <linux/nls.h>
 #include <linux/usb/composite.h>
 #include <linux/usb/gadget_configfs.h>
···
 	bool use;
 
 	mutex_lock(&gi->lock);
-	ret = strtobool(page, &use);
+	ret = kstrtobool(page, &use);
 	if (!ret) {
 		gi->use_os_desc = use;
 		ret = len;

drivers/usb/gadget/function/f_mass_storage.c

···
 #include <linux/fcntl.h>
 #include <linux/file.h>
 #include <linux/fs.h>
+#include <linux/kstrtox.h>
 #include <linux/kthread.h>
 #include <linux/sched/signal.h>
 #include <linux/limits.h>
···
 		return -EBUSY;
 	}
 
-	ret = strtobool(page, &stall);
+	ret = kstrtobool(page, &stall);
 	if (!ret) {
 		opts->common->can_stall = stall;
 		ret = len;

drivers/usb/gadget/function/storage_common.c

···
 #include <linux/blkdev.h>
 #include <linux/file.h>
 #include <linux/fs.h>
+#include <linux/kstrtox.h>
 #include <linux/usb/composite.h>
 
 #include "storage_common.h"
···
 	ssize_t		rc;
 	bool		ro;
 
-	rc = strtobool(buf, &ro);
+	rc = kstrtobool(buf, &ro);
 	if (rc)
 		return rc;
 
···
 	bool		nofua;
 	int		ret;
 
-	ret = strtobool(buf, &nofua);
+	ret = kstrtobool(buf, &nofua);
 	if (ret)
 		return ret;
 
···
 	bool		cdrom;
 	int		ret;
 
-	ret = strtobool(buf, &cdrom);
+	ret = kstrtobool(buf, &cdrom);
 	if (ret)
 		return ret;
 
···
 	bool		removable;
 	int		ret;
 
-	ret = strtobool(buf, &removable);
+	ret = kstrtobool(buf, &removable);
 	if (ret)
 		return ret;
 

drivers/usb/gadget/function/u_serial.c

···
 #include <linux/export.h>
 #include <linux/module.h>
 #include <linux/console.h>
+#include <linux/kstrtox.h>
 #include <linux/kthread.h>
 #include <linux/workqueue.h>
 #include <linux/kfifo.h>
···
 	bool enable;
 	int ret;
 
-	ret = strtobool(page, &enable);
+	ret = kstrtobool(page, &enable);
 	if (ret)
 		return ret;
 

drivers/usb/gadget/legacy/serial.c

···
 
 #include <linux/kernel.h>
 #include <linux/device.h>
+#include <linux/kstrtox.h>
 #include <linux/module.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
···
 	if (!s)	/* called for no-arg enable == default */
 		return 0;
 
-	ret = strtobool(s, &do_enable);
+	ret = kstrtobool(s, &do_enable);
 	if (ret || enable == do_enable)
 		return ret;