Changed from using the cxx variable to directly using g++

Makefile

@@ -1,10 +1,8 @@
-cxx = g++
-
 all:
-	cxx *.cpp -O3 -Wall -Wextra -std=c++17 -o lottery
+	g++ *.cpp -O3 -Wall -Wextra -std=c++17 -o lottery
 
 compile:
-	cxx *.cpp -O3 -c
+	g++ *.cpp -O3 -c
 
 debug:
-	cxx *.cpp -g -std=c++17 -o calculator -lstdc++ -lm
+	g++ *.cpp -g -std=c++17 -o calculator -lstdc++ -lm