[RTL] remove redundant error in type parser.

This also fixes a clang tidy issue I introduced in a previous patch.

include/circt/Dialect/RTL/Types.h

@@ -19,7 +19,7 @@ class DialectAsmPrinter;
 namespace circt {
 namespace rtl {
 using Location = ::mlir::Location;
-}
+} // namespace rtl
 } // namespace circt
 
 #define GET_TYPEDEF_CLASSES

lib/Dialect/RTL/Dialect.cpp

@@ -83,12 +83,7 @@ Type RTLDialect::parseType(DialectAsmParser &parser) const {
   llvm::StringRef mnemonic;
   if (parser.parseKeyword(&mnemonic))
     return Type();
-  auto genType = generatedTypeParser(getContext(), parser, mnemonic);
-  if (genType)
-    return genType;
-  parser.emitError(parser.getCurrentLocation(), "Could not parse rtl.")
-      << mnemonic << ".";
-  return Type();
+  return generatedTypeParser(getContext(), parser, mnemonic);
 }
 
 /// Print a type registered to this dialect. Try the tblgen'd type printer

test/rtl/errors.mlir

@@ -67,12 +67,10 @@ rtl.module @B() {
 
 // -----
 
-// expected-error @+2 {{rtl.array only supports one dimension}}
-// expected-error @+1 {{Could not parse rtl.array}}
+// expected-error @+1 {{rtl.array only supports one dimension}}
 func @arrayDims(%a: !rtl.array<3 x 4 x i5>) { }
 
 // -----
 
-// expected-error @+2 {{invalid element for rtl.inout type}}
-// expected-error @+1 {{Could not parse rtl.inout}}
+// expected-error @+1 {{invalid element for rtl.inout type}}
 func @invalidInout(%arg0: !rtl.inout<tensor<*xf32>>) { }