[mlir] Fix warnings about extra ';'

This patch fixes:

  mlir/include/mlir/Bytecode/BytecodeImplementation.h:415:4: warning:
  extra ‘;’ [-Wpedantic]

  mlir/include/mlir/Bytecode/BytecodeWriter.h:110:4: warning: extra
  ‘;’ [-Wpedantic]

Author: kazutakahirata

mlir/include/mlir/Bytecode/BytecodeImplementation.h

@@ -412,7 +412,7 @@ class DialectBytecodeWriter {
   template <class T>
   FailureOr<const DialectVersion *> getDialectVersion() const {
     return getDialectVersion(T::getDialectNamespace());
-  };
+  }
 };
 
 //===----------------------------------------------------------------------===//

mlir/include/mlir/Bytecode/BytecodeWriter.h

@@ -107,7 +107,7 @@ class BytecodeWriterConfig {
   void setDialectVersion(std::unique_ptr<DialectVersion> dialectVersion) const {
     return setDialectVersion(T::getDialectNamespace(),
                              std::move(dialectVersion));
-  };
+  }
   void setDialectVersion(StringRef dialectName,
                          std::unique_ptr<DialectVersion> dialectVersion) const;