fs/vfs/fs_close.c: avoid double free if CONFIG_FS_NOTIFY is set

Double free occurred in lib_put_pathbuffer if CONFIG_FS_NOTIFY option
was enabled. The second if statement has to be called only if the
close operation returned error. The bug was introduced in 14f5c48
and was causing misc/lib_tempbuffer.c:141 debug assertion.

Signed-off-by: Michal Lenc <michallenc@seznam.cz>

fs/vfs/fs_close.c

@@ -139,9 +139,8 @@ int file_close(FAR struct file *filep)
 
           inode_release(inode);
         }
-
 #ifdef CONFIG_FS_NOTIFY
-      if (path != NULL)
+      else if (path != NULL)
         {
           lib_put_pathbuffer(path);
         }