solana: Fix style on err handling

Author: johnsaigle

solana/programs/ntt-quoter/src/error.rs

@@ -1,3 +1,5 @@
+use std::num::TryFromIntError;
+
 #[anchor_lang::prelude::error_code]
 pub enum NttQuoterError {
     #[msg("Relay fees exceeds specified max")]
@@ -30,3 +32,9 @@ pub enum NttQuoterError {
     #[msg("The price cannot be zero")]
     PriceCannotBeZero = 0x103,
 }
+
+impl From<TryFromIntError> for NttQuoterError {
+    fn from(_: TryFromIntError) -> Self {
+        Self::ScalingOverflow
+    }
+}

solana/programs/ntt-quoter/src/processor/request_relay.rs

@@ -103,11 +103,8 @@ fn mul_div(scalar: u64, numerator: u64, denominator: u64) -> StdResult<u64, NttQ
     if scalar == 0 || numerator == 0 {
         return Ok(0);
     }
-
     u64::try_from(u128::from(scalar) * u128::from(numerator) / u128::from(denominator))
-        .map_or(Err(NttQuoterError::ScalingOverflow), |quotient| {
-            Ok(quotient)
-        })
+        .map_err(NttQuoterError::from)
 }
 
 pub fn request_relay(ctx: Context<RequestRelay>, args: RequestRelayArgs) -> Result<()> {