cifs: Fix crash on unload of cifs_arc4.ko

The exit function is wrongly placed in the __init section and this leads
to a crash when the module is unloaded.  Just remove both the init and
exit functions since this module does not need them.

Fixes: 71c02863 ("cifs: fork arc4 and create a separate module...")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org # 5.15
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smbfs_common/cifs_arc4.c

@@ -72,16 +72,3 @@ void cifs_arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in, unsigned int l
 	ctx->y = y;
 }
 EXPORT_SYMBOL_GPL(cifs_arc4_crypt);
-
-static int __init
-init_smbfs_common(void)
-{
-	return 0;
-}
-static void __init
-exit_smbfs_common(void)
-{
-}
-
-module_init(init_smbfs_common)
-module_exit(exit_smbfs_common)