block: blk-crypto-fallback: remove redundant initialization of variable err

The variable err is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NSatya Tangirala <satyat@google.com>
Addresses-Coverity: ("Unused value")
Signed-off-by: NJens Axboe <axboe@kernel.dk>

block/blk-crypto-fallback.c

@@ -529,7 +529,7 @@ static bool blk_crypto_fallback_inited;
 static int blk_crypto_fallback_init(void)
 {
 	int i;
-	int err = -ENOMEM;
+	int err;
 
 	if (blk_crypto_fallback_inited)
 		return 0;