scripts: Fixed make summary-diff, adopted -Q/--small-table

Looks like this was never updated after changing the -Y/--summary +
-c/--compare hack to its own -Q/--small-table flag. Fortunately a single
character fix.

Unrelated, but I was considering dropping the make *-diff rules, until
the different compile-time targets proved they are _very_ useful when
jumping around various commits/builds.

Makefile

@@ -404,7 +404,7 @@ summary-diff sizes-diff: $(OBJ) $(CI)
 				-fctx='max(size)' -q -o-) \
 			-fcode -fdata -fstack='max(stack)' -fctx='max(ctx)' \
 			-bbuild='"BEFORE"' -q -o-) \
-		-bbuild -cBEFORE -Y $(SUMMARYFLAGS))
+		-bbuild -cBEFORE -Q $(SUMMARYFLAGS))
 
 ## Build the test-runner
 .PHONY: test-runner build-tests