Kernel: Misc tweaks

Author: https://github.com/bugaevc
Commit: d395b93b15
Pull-request: https://github.com/SerenityOS/serenity/pull/2430
Reviewed-by: https://github.com/alimpfard

Kernel/FileSystem/VirtualFileSystem.h

@@ -132,8 +132,7 @@ private:
     Lock m_lock { "VFSLock" };
 
     RefPtr<Inode> m_root_inode;
-    Vector<Mount> m_mounts;
-
+    Vector<Mount, 16> m_mounts;
     RefPtr<Custody> m_root_custody;
 };