ecryptfs: string copy cleanup

Clean up overcomplicated string copy, which also gets rid of this
bogus warning:

fs/ecryptfs/main.c: In function 'ecryptfs_parse_options':
include/asm/arch/string_32.h:75: warning: array subscript is above array bounds
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ecryptfs/main.c

@@ -301,7 +301,6 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options)
 	char *cipher_name_dst;
 	char *cipher_name_src;
 	char *cipher_key_bytes_src;
-	int cipher_name_len;
 
 	if (!options) {
 		rc = -EINVAL;
@@ -382,17 +381,12 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options)
 		goto out;
 	}
 	if (!cipher_name_set) {
-		cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
-		if (unlikely(cipher_name_len
-			     >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) {
-			rc = -EINVAL;
-			BUG();
-			goto out;
-		}
-		memcpy(mount_crypt_stat->global_default_cipher_name,
-		       ECRYPTFS_DEFAULT_CIPHER, cipher_name_len);
-		mount_crypt_stat->global_default_cipher_name[cipher_name_len]
-		    = '\0';
+		int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
+
+		BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
+
+		strcpy(mount_crypt_stat->global_default_cipher_name,
+		       ECRYPTFS_DEFAULT_CIPHER);
 	}
 	if (!cipher_key_bytes_set) {
 		mount_crypt_stat->global_default_cipher_key_size = 0;