core/hle/result: Remove now-unused constructor for ResultCode

Now that the final stray ErrorDescription member was relocated, we can
finally remove it and its relevant constructor in the ResultCode union.

src/core/hle/result.h

@@ -12,13 +12,6 @@
 
 // All the constants in this file come from http://switchbrew.org/index.php?title=Error_codes
 
-/**
- * Detailed description of the error. Code 0 always means success.
- */
-enum class ErrorDescription : u32 {
-    Success = 0,
-};
-
 /**
  * Identifies the module which caused the error. Error codes can be propagated through a call
  * chain, meaning that this doesn't always correspond to the module where the API call made is
@@ -132,9 +125,6 @@ union ResultCode {
 
     constexpr explicit ResultCode(u32 raw) : raw(raw) {}
 
-    constexpr ResultCode(ErrorModule module, ErrorDescription description)
-        : ResultCode(module, static_cast<u32>(description)) {}
-
     constexpr ResultCode(ErrorModule module_, u32 description_)
         : raw(module.FormatValue(module_) | description.FormatValue(description_)) {}