fs_inode:Change the type of i_crefs to atomic_int

Summary:
  1.Modified the i_crefs from int16_t to atomic_int
  2.Modified the i_crefs add, delete, read, and initialize interfaces to atomic operations
The purpose of this change is to avoid deadlock in cross-core scenarios, where A Core blocks B Core’s request for a write operation to A Core when A Core requests a read operation to B Core.

Signed-off-by: chenrun1 <chenrun1@xiaomi.com>

fs/mqueue/mq_open.c

@@ -74,7 +74,7 @@ static int nxmq_file_close(FAR struct file *filep)
 {
   FAR struct inode *inode = filep->f_inode;
 
-  if (inode->i_crefs <= 0)
+  if (atomic_load(&inode->i_crefs) <= 0)
     {
       FAR struct mqueue_inode_s *msgq = inode->i_private;
 
@@ -322,7 +322,7 @@ static int file_mq_vopen(FAR struct file *mq, FAR const char *mq_name,
 
       /* Set the initial reference count on this inode to one */
 
-      inode->i_crefs++;
+      atomic_fetch_add(&inode->i_crefs, 1);
 
       if (created)
         {

fs/mqueue/mq_unlink.c

@@ -56,7 +56,7 @@
 
 static void mq_inode_release(FAR struct inode *inode)
 {
-  if (inode->i_crefs <= 1)
+  if (atomic_load(&inode->i_crefs) <= 1)
     {
       FAR struct mqueue_inode_s *msgq = inode->i_private;