Annotate sys_uselib() with user pointer annotation

fs/exec.c

@@ -111,7 +111,7 @@ static inline void put_binfmt(struct linux_binfmt * fmt)
  *
  * Also note that we take the address to load from from the file itself.
  */
-asmlinkage long sys_uselib(const char * library)
+asmlinkage long sys_uselib(const char __user * library)
 {
 	struct file * file;
 	struct nameidata nd;