File etw-fix-build.patch of Package etw

diff -Nur etw-3.6-orig/Makefile.linux etw-3.6/Makefile.linux
--- etw-3.6-orig/Makefile.linux	2007-10-14 22:45:17.000000000 +0200
+++ etw-3.6/Makefile.linux	2023-01-28 08:47:43.642557456 +0100
@@ -1,9 +1,9 @@
 CC = gcc
 
 CFLAGS = -Wall -Wno-char-subscripts -g -fsigned-char -Iinclude \
-  `pkg-config --cflags sdl` `pkg-config --cflags gtk+-2.0`
+  -std=gnu89 `pkg-config --cflags sdl` `pkg-config --cflags gtk+-2.0`
 
-LDFLAGS = `pkg-config --libs sdl` `pkg-config --libs gtk+-2.0`
+LDFLAGS = `pkg-config --libs sdl` `pkg-config --libs gtk+-2.0` -lm -pthread
 DEFINES = -DLINUX -DCD_VERSION -DENABLE_BINRELOC -DHAVE_STDINT_H
 
 OBJECTS = highdirent.o cpu.o human.o myiff.o specials.o \