engine: show additional errno string when log file cannot be opened

engine/common/sys_con.c

@@ -17,6 +17,8 @@ GNU General Public License for more details.
 #if XASH_ANDROID
 #include <android/log.h>
 #endif
+#include <string.h>
+#include <errno.h>
 
 #if !XASH_WIN32 && !XASH_MOBILE_PLATFORM
 #define XASH_COLORIZE_CONSOLE
@@ -115,7 +117,7 @@ void Sys_InitLog( void )
 		s_ld.logfile = fopen( s_ld.log_path, mode );
 		if( !s_ld.logfile )
 		{
-			Con_Reportf( S_ERROR  "Sys_InitLog: can't create log file %s\n", s_ld.log_path );
+			Con_Reportf( S_ERROR  "Sys_InitLog: can't create log file %s: %s\n", s_ld.log_path, strerror( errno ) );
 		}
 		else
 		{