fs: Make unload_nls() NULL pointer safe

Most call sites of unload_nls() do:
	if (nls)
		unload_nls(nls);

Check the pointer inside unload_nls() like we do in kfree() and
simplify the call sites.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steve French <sfrench@us.ibm.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Petr Vandrovec <vandrove@vc.cvut.cz>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index c0759fe..43022f3 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -229,8 +229,7 @@
 	iput(HFSPLUS_SB(sb).alloc_file);
 	iput(HFSPLUS_SB(sb).hidden_dir);
 	brelse(HFSPLUS_SB(sb).s_vhbh);
-	if (HFSPLUS_SB(sb).nls)
-		unload_nls(HFSPLUS_SB(sb).nls);
+	unload_nls(HFSPLUS_SB(sb).nls);
 	kfree(sb->s_fs_info);
 	sb->s_fs_info = NULL;
 
@@ -464,8 +463,7 @@
 
 cleanup:
 	hfsplus_put_super(sb);
-	if (nls)
-		unload_nls(nls);
+	unload_nls(nls);
 	return err;
 }