dput(): turn into explicit while() loop

No need to mess with gotos when the code yielded by straight while()
isn't any worse...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs/dcache.c

@@ -828,10 +828,7 @@ static inline bool fast_dput(struct dentry *dentry)
  */
 void dput(struct dentry *dentry)
 {
-	if (unlikely(!dentry))
-		return;
-
-repeat:
+	while (dentry) {
 		might_sleep();
 
 		rcu_read_lock();
@@ -849,8 +846,6 @@ void dput(struct dentry *dentry)
 		}
 
 		dentry = dentry_kill(dentry);
-	if (dentry) {
-		goto repeat;
 	}
 }
 EXPORT_SYMBOL(dput);