usb: gadget: f_fs: Accept up to 30 endpoints.

It is allowed by the USB specification to enabled same-address, opposite-
direction endpoints simultaneously, which means 30 non-zero endpoints
are allowed. So double eps_addrmap length to 30.
The original code only accepted 14 descriptors out of a likely intended 15
(as there are 15 endpoint addresses, ignoring direction), because the first
eps_addrmap entry is unused (it is a placeholder for endpoint zero). So
increase eps_addrmap length by one to 31.
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

@@ -2101,7 +2101,7 @@ static int __ffs_data_do_entity(enum ffs_entity_type type,
 	case FFS_ENDPOINT:
 		d = (void *)desc;
 		helper->eps_count++;
-		if (helper->eps_count >= 15)
+		if (helper->eps_count >= FFS_MAX_EPS_COUNT)
 			return -EINVAL;
 		/* Check if descriptors for any speed were already parsed */
 		if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)

drivers/usb/gadget/function/u_fs.h

@@ -247,7 +247,8 @@ struct ffs_data {
 
 	unsigned			user_flags;
 
-	u8				eps_addrmap[15];
+#define FFS_MAX_EPS_COUNT 31
+	u8				eps_addrmap[FFS_MAX_EPS_COUNT];
 
 	unsigned short			strings_count;
 	unsigned short			interfaces_count;