cryptfs: Remove unused variable

We'll be allowing modifyable key sizes in the near future,
and want to remove this variable to reduce confusion with this
change.

Bug: 73079191
Test: None
Change-Id: I7047bb375553d8c46ff0724add697a5105ebc68c

cryptfs.cpp

@@ -1056,7 +1056,6 @@ static int scrypt(const char *passwd, const unsigned char *salt,
     int p = 1 << ftr->p_factor;
 
     /* Turn the password into a key and IV that can decrypt the master key */
-    unsigned int keysize;
     crypto_scrypt((const uint8_t*)passwd, strlen(passwd),
                   salt, SALT_LEN, N, r, p, ikey,
                   KEY_LEN_BYTES + IV_LEN_BYTES);