engine: common: remove unneeded REF_DLL ifdef, keep #error anyway

engine/common/common.h

@@ -515,7 +515,6 @@ qboolean Mem_IsAllocatedExt( byte *poolptr, void *data );
 void Mem_PrintList( size_t minallocationsize );
 void Mem_PrintStats( void );
 
-#ifndef REF_DLL
 #define Mem_Malloc( pool, size ) _Mem_Alloc( pool, size, false, __FILE__, __LINE__ )
 #define Mem_Calloc( pool, size ) _Mem_Alloc( pool, size, true, __FILE__, __LINE__ )
 #define Mem_Realloc( pool, ptr, size ) _Mem_Realloc( pool, ptr, size, true, __FILE__, __LINE__ )
@@ -525,7 +524,6 @@ void Mem_PrintStats( void );
 #define Mem_EmptyPool( pool ) _Mem_EmptyPool( pool, __FILE__, __LINE__ )
 #define Mem_IsAllocated( mem ) Mem_IsAllocatedExt( NULL, mem )
 #define Mem_Check() _Mem_Check( __FILE__, __LINE__ )
-#endif
 
 //
 // filesystem.c