fs/driver: change unlink to nx_unlink to avoid setting errno

Signed-off-by: Juha Niskanen <juha.niskanen@haltian.com>

fs/driver/driver.h

@@ -130,16 +130,8 @@ int block_proxy(FAR struct file *filep, FAR const char *blkdev, int oflags);
  * Returned Value:
  *   If zero, non-zero inode pointer is returned on success.  This
  *   is the inode pointer of the nameless block driver that mediates
- *   accesses to the mtd driver.
+ *   accesses to the mtd driver. A negated errno value is returned on
- *
+ *   any failure.
- *   Errors that may be returned:
- *
- *     ENOMEM - Failed to create a temporary path name.
- *
- *   Plus:
- *
- *     - Errors reported from ftl_initialize()
- *     - Errors reported from open() or unlink()
  *
  ****************************************************************************/
 

fs/driver/fs_blockproxy.c

@@ -186,10 +186,9 @@ int block_proxy(FAR struct file *filep, FAR const char *blkdev, int oflags)
    * a problem here!)
    */
 
-  ret = unlink(chardev);
+  ret = nx_unlink(chardev);
   if (ret < 0)
     {
-      ret = -errno;
       ferr("ERROR: Failed to unlink %s: %d\n", chardev, ret);
       goto errout_with_chardev;
     }
@@ -200,7 +199,7 @@ int block_proxy(FAR struct file *filep, FAR const char *blkdev, int oflags)
   return OK;
 
 errout_with_bchdev:
-  unlink(chardev);
+  nx_unlink(chardev);
 
 errout_with_chardev:
   kmm_free(chardev);

fs/driver/fs_mtdproxy.c

@@ -131,16 +131,8 @@ static FAR char *unique_blkdev(void)
  * Returned Value:
  *   If zero, non-zero inode pointer is returned on success.  This
  *   is the inode pointer of the nameless block driver that mediates
- *   accesses to the mtd driver.
+ *   accesses to the mtd driver. A negated errno value is returned on
- *
+ *   any failure.
- *   Errors that may be returned:
- *
- *     ENOMEM - Failed to create a temporary path name.
- *
- *   Plus:
- *
- *     - Errors reported from ftl_initialize()
- *     - Errors reported from open() or unlink()
  *
  ****************************************************************************/
 
@@ -193,7 +185,7 @@ int mtd_proxy(FAR const char *mtddev, int mountflags,
    */
 
 out_with_fltdev:
-  unlink(blkdev);
+  nx_unlink(blkdev);
 out_with_blkdev:
   kmm_free(blkdev);
   return ret;