generator: Limit pCode member workaround to VkShaderModuleCreateInfo (#707)

An upcoming extension will ship with an untyped `pCode` member (`void
*`) including a valid `len` field pointing to a `codeSize` field rather
than obscure Latex math and a `/4` expression in `altlen`.  Limit the
scope of our workaround for that SPIR-V-specific `pCode` field to
`VkShaderModuleCreateInfo`.

generator/src/lib.rs

@@ -1659,7 +1659,7 @@ pub fn derive_setters(
             }
 
             // Unique cases
-            if name == "pCode" {
+            if struct_.name == "VkShaderModuleCreateInfo" && name == "pCode" {
                 return Some(quote!{
                     #[inline]
                     pub fn code(mut self, code: &'a [u32]) -> Self {