cifsd: fix WARNING: unmet direct dependencies detected for CRYPTO_ARC4

Randy reported warning message from fs/cifsd/Kconfig.

WARNING: unmet direct dependencies detected for CRYPTO_ARC4
  Depends on [n]: CRYPTO [=y] && CRYPTO_USER_API_ENABLE_OBSOLETE [=n]
  Selected by [y]:
  - SMB_SERVER [=y] && NETWORK_FILESYSTEMS [=y] && INET [=y]

arc4 library is not currently in use. So this patch eliminates
unnecessary library set in cifsd.
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

fs/cifsd/Kconfig

@@ -7,7 +7,6 @@ config SMB_SERVER
 	select CRYPTO_MD4
 	select CRYPTO_MD5
 	select CRYPTO_HMAC
-	select CRYPTO_ARC4
 	select CRYPTO_ECB
 	select CRYPTO_LIB_DES
 	select CRYPTO_SHA256

fs/cifsd/server.c

@@ -618,7 +618,6 @@ MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
 MODULE_VERSION(KSMBD_VERSION);
 MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
 MODULE_LICENSE("GPL");
-MODULE_SOFTDEP("pre: arc4");
 MODULE_SOFTDEP("pre: ecb");
 MODULE_SOFTDEP("pre: hmac");
 MODULE_SOFTDEP("pre: md4");