Relax the clippy checks in CI, address a lint warning

Author: jessebraham

.github/workflows/rust.yml

@@ -106,6 +106,5 @@ jobs:
       - uses: actions-rs/cargo@v1
         with:
           command: clippy
-          # `identity_op` and `or_fun_call` may lead to false positives
           # `too_many_arguments` is relatively arbitrary
-          args: -- -D warnings -A clippy::identity_op -A clippy::or_fun_call -A clippy::too_many_arguments
+          args: -- -A clippy::too_many_arguments

espflash/src/partition_table.rs

@@ -739,7 +739,7 @@ where
     let buf = String::deserialize(deserializer)?;
     let buf = buf.trim();
 
-    parse_int::parse::<u8>(buf).or(Err(Error::custom("invalid data sub-type")))
+    parse_int::parse::<u8>(buf).map_err(|_| Error::custom("invalid data sub-type"))
 }
 
 fn deserialize_partition_offset_or_size<'de, D>(deserializer: D) -> Result<Option<u32>, D::Error>