exfat: optimize and fix compile warnring

Change-Id: I86f037e6929aacc9e4dffd3a88bf3abc90932a12
Signed-off-by: Jiuzhu Dong <dongjiuzhu1@xiaomi.com>

fs/exfat/config.h

@@ -1,6 +1,8 @@
 /* libexfat/config.h.  Generated from config.h.in by configure.  */
 /* libexfat/config.h.in.  Generated from configure.ac by autoheader.  */
 
+#include <nuttx/config.h>
+
 /* Name of package */
 #define PACKAGE "exfat"
 
@@ -44,3 +46,7 @@
 
 /* Enable pread() and pwrite(). */
 #define _XOPEN_SOURCE 500
+
+#ifndef CONFIG_LIBC_LOCALTIME
+void tzset(void);
+#endif

fs/exfat/exfat_vfs.c

@@ -221,7 +221,7 @@ static int exfatfs_getpath(FAR struct inode *inode,
     }
 
   path += strlen(path);
-  exfat_get_name(node, path);
+  strcpy(path, node->name);
   if (node->child)
     {
       strcat(path, "/");
@@ -930,7 +930,7 @@ static int exfatfs_readdir(FAR struct inode *mountpt,
           dir->fd_dir.d_type = DTYPE_FILE;
         }
 
-      exfat_get_name(priv->entry, dir->fd_dir.d_name);
+      strcpy(dir->fd_dir.d_name, priv->entry->name);
       node = priv->entry;
       priv->entry = exfat_readdir(&priv->it);
       exfatfs_release_node(&fs->ef, node);