usb: gadget: f_fs: fix wrong parenthesis in ffs_func_req_match()

Properly check the return code of ffs_func_revmap_intf() and
ffs_func_revmap_ep() for a non-negative value.

Instead of checking the return code, the comparison was performed for the last
parameter of the function calls, because of wrong parenthesis.

This also fixes the following static checker warning:
drivers/usb/gadget/function/f_fs.c:3152 ffs_func_req_match()
warn: always true condition '(((creq->wIndex)) >= 0) => (0-u16max >= 0)'
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NFelix Hädicke <felixhaedicke@web.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/function/f_fs.c

@@ -3225,11 +3225,11 @@ static bool ffs_func_req_match(struct usb_function *f,
 
 	switch (creq->bRequestType & USB_RECIP_MASK) {
 	case USB_RECIP_INTERFACE:
-		return ffs_func_revmap_intf(func,
-					    le16_to_cpu(creq->wIndex) >= 0);
+		return (ffs_func_revmap_intf(func,
+					     le16_to_cpu(creq->wIndex)) >= 0);
 	case USB_RECIP_ENDPOINT:
-		return ffs_func_revmap_ep(func,
-					  le16_to_cpu(creq->wIndex) >= 0);
+		return (ffs_func_revmap_ep(func,
+					   le16_to_cpu(creq->wIndex)) >= 0);
 	default:
 		return (bool) (func->ffs->user_flags &
 			       FUNCTIONFS_ALL_CTRL_RECIP);