clippy: fix single_match_else lint

Just style, and apologies for the annoying-to-review diff that moves
logic around. But the result is more consistent and (I think) better.

Author: apoelstra

src/address.rs

@@ -494,19 +494,11 @@ impl Address {
         // When blinded, the structure is:
         // <1: blinding prefix> <1: regular prefix> <33: blinding pubkey> <20: hash160>
 
-        let (blinded, prefix) = match data[0] == params.blinded_prefix {
-            true => {
-                if data.len() != 55 {
-                    return Err(AddressError::InvalidLength(data.len()));
-                }
-                (true, data[1])
-            }
-            false => {
-                if data.len() != 21 {
-                    return Err(AddressError::InvalidLength(data.len()));
-                }
-                (false, data[0])
-            }
+        let blinded = data[0] == params.blinded_prefix;
+        let prefix = match (blinded, data.len()) {
+            (true, 55) => data[1],
+            (false, 21) => data[0],
+            (_, len) => return Err(AddressError::InvalidLength(len)),
         };
 
         let (blinding_pubkey, payload_data) = match blinded {

src/script.rs

@@ -485,29 +485,38 @@ impl Script {
                             f.write_str("<unexpected end>")?;
                             break;
                         }
-                        match read_uint(&self.0[index..], 1) {
-                            Ok(n) => { index += 1; n }
-                            Err(_) => { f.write_str("<bad length>")?; break; }
+                        if let Ok(n) =read_uint(&self.0[index..], 1) {
+                            index += 1;
+                            n
+                        } else {
+                            f.write_str("<bad length>")?;
+                            break;
                         }
                     }
                     opcodes::all::OP_PUSHDATA2 => {
                         if self.0.len() < index + 2 {
                             f.write_str("<unexpected end>")?;
                             break;
                         }
-                        match read_uint(&self.0[index..], 2) {
-                            Ok(n) => { index += 2; n }
-                            Err(_) => { f.write_str("<bad length>")?; break; }
+                        if let Ok(n) = read_uint(&self.0[index..], 2) {
+                            index += 2;
+                            n
+                        } else {
+                            f.write_str("<bad length>")?;
+                            break;
                         }
                     }
                     opcodes::all::OP_PUSHDATA4 => {
                         if self.0.len() < index + 4 {
                             f.write_str("<unexpected end>")?;
                             break;
                         }
-                        match read_uint(&self.0[index..], 4) {
-                            Ok(n) => { index += 4; n }
-                            Err(_) => { f.write_str("<bad length>")?; break; }
+                        if let Ok(n) = read_uint(&self.0[index..], 4) {
+                            index += 4;
+                            n
+                        } else {
+                            f.write_str("<bad length>")?;
+                            break;
                         }
                     }
                     _ => 0