common_funcs: Remove check for VS versions that we don't even support

We don't support any VS versions that don't already have snprintf in the
standard library implementation.

src/common/common_funcs.h

@@ -74,11 +74,6 @@ inline u64 _rotr64(u64 x, unsigned int shift) {
 
 #else // _MSC_VER
 
-#if (_MSC_VER < 1900)
-// Function Cross-Compatibility
-#define snprintf _snprintf
-#endif
-
 // Locale Cross-Compatibility
 #define locale_t _locale_t