While at it, combine the check for ANDROID with the ones for WNT and HAIKU

Also, order them alphabetically.

Change-Id: I144331d71455c1c794d300f9a4f4e2e21fcd5e1b

sal/Library_sal.mk

@@ -57,10 +57,8 @@ $(eval $(call gb_Library_use_system_win32_libs,sal,\
 ))
 
 $(eval $(call gb_Library_add_libs,sal,\
-	$(if $(filter-out WNT HAIKU,$(OS)), \
-		$(if $(filter $(OS),ANDROID),, \
-			-lpthread \
-		) \
+	$(if $(filter-out ANDROID HAIKU WNT,$(OS)), \
+		-lpthread \
 	) \
 	$(if $(filter $(OS),LINUX), \
 		-ldl \