usb: gadget: ffs: Make sparse happier

Silences the following warnings:
drivers/usb/gadget/function/f_fs.c:1253:37: warning: incorrect type in argument 1 (different address spaces)
drivers/usb/gadget/function/f_fs.c:1253:37:    expected void [noderef] <asn:1>*to
drivers/usb/gadget/function/f_fs.c:1253:37:    got void *<noident>
drivers/usb/gadget/function/f_fs.c:2322:23: warning: cast to restricted __le32
drivers/usb/gadget/function/f_fs.c:2876:38: warning: cast to restricted __le32
drivers/usb/gadget/function/f_fs.c:272:12: warning: context imbalance in '__ffs_ep0_queue_wait' - unexpected unlock
drivers/usb/gadget/function/f_fs.c:450:17: warning: context imbalance in 'ffs_ep0_write' - different lock contexts for basic block
drivers/usb/gadget/function/f_fs.c:490:24: warning: context imbalance in '__ffs_ep0_read_events' - unexpected unlock
drivers/usb/gadget/function/f_fs.c:496:16: warning: context imbalance in 'ffs_ep0_read' - different lock contexts for basic block

Also, add an "unlocks spinlock" comment for consistency with existing ones.
No behaviour change is intended.
Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/function/f_fs.c

@@ -266,6 +266,7 @@ static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
 }
 
 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
+	__releases(&ffs->ev.waitq.lock)
 {
 	struct usb_request *req = ffs->ep0req;
 	int ret;
@@ -458,6 +459,7 @@ static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
 				     size_t n)
+	__releases(&ffs->ev.waitq.lock)
 {
 	/*
 	 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
@@ -543,6 +545,7 @@ static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 			break;
 		}
 
+		/* unlocks spinlock */
 		return __ffs_ep0_read_events(ffs, buf,
 					     min(n, (size_t)ffs->ev.count));
 
@@ -1246,7 +1249,7 @@ static long ffs_epfile_ioctl(struct file *file, unsigned code,
 		desc = epfile->ep->descs[desc_idx];
 
 		spin_unlock_irq(&epfile->ffs->eps_lock);
-		ret = copy_to_user((void *)value, desc, desc->bLength);
+		ret = copy_to_user((void __user *)value, desc, desc->bLength);
 		if (ret)
 			ret = -EFAULT;
 		return ret;
@@ -2324,7 +2327,7 @@ static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
 				  length, pnl, type);
 			return -EINVAL;
 		}
-		pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
+		pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl));
 		if (length != 14 + pnl + pdl) {
 			pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
 				  length, pnl, pdl, type);
@@ -2878,7 +2881,7 @@ static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
 
 		ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
 		ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
-		ext_prop->data_len = le32_to_cpu(*(u32 *)
+		ext_prop->data_len = le32_to_cpu(*(__le32 *)
 			usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
 		length = ext_prop->name_len + ext_prop->data_len + 14;