cifs: fix trivial typo

Typo: exiting --> existing
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/connect.c

@@ -2911,7 +2911,7 @@ static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
 #ifdef CONFIG_CIFS_DFS_UPCALL
 /*
  * cifs_build_path_to_root returns full path to root when we do not have an
- * exiting connection (tcon)
+ * existing connection (tcon)
  */
 static char *
 build_unc_path_to_root(const struct smb3_fs_context *ctx,