common_types: Remove unnecessary check for whether or not__func__ is defined

VS has supported this for quite a while.

src/common/common_types.h

@@ -27,12 +27,6 @@
 #include <array>
 #include <cstdint>
 
-#ifdef _MSC_VER
-#ifndef __func__
-#define __func__ __FUNCTION__
-#endif
-#endif
-
 typedef std::uint8_t u8;   ///< 8-bit unsigned byte
 typedef std::uint16_t u16; ///< 16-bit unsigned short
 typedef std::uint32_t u32; ///< 32-bit unsigned word