[lldb] Remove an unnecessary cast (NFC) (#152642)

type is already of lldb::SymbolType.

Author: kazutakahirata

lldb/include/lldb/Symbol/Symbol.h

@@ -167,7 +167,7 @@ class Symbol : public SymbolContextScope {
 
   lldb::SymbolType GetType() const { return (lldb::SymbolType)m_type; }
 
-  void SetType(lldb::SymbolType type) { m_type = (lldb::SymbolType)type; }
+  void SetType(lldb::SymbolType type) { m_type = type; }
 
   const char *GetTypeAsString() const;