Merge pull request #829 from PX4/uploader_hotfix

Hotfix to PX4IO uploader. There are no known mishaps due to it, but very...

src/drivers/px4io/px4io_uploader.cpp

@@ -201,9 +201,14 @@ PX4IO_Uploader::upload(const char *filenames[])
 			continue;
 		}
 
-		if (bl_rev <= 2)
+		if (bl_rev <= 2) {
 			ret = verify_rev2(fw_size);
-		else if(bl_rev == 3) {
+		} else if(bl_rev == 3) {
+			ret = verify_rev3(fw_size);
+		} else {
+			/* verify rev 4 and higher still uses the same approach and
+			 * every version *needs* to be verified.
+			 */
 			ret = verify_rev3(fw_size);
 		}