""security"" also make it compile on alpine

Makefile

@@ -3,7 +3,7 @@ BIN=udo
 
 all:
 	mkdir -p bin
-	gcc $(CFLAGS) $(wildcard src/*.c) -o bin/udo
+	gcc $(wildcard src/*.c) -o bin/udo $(CFLAGS) 
 
 install: all
 	cp bin/udo /usr/local/bin/udo

src/main.c

@@ -8,7 +8,7 @@
 #include <security/pam_misc.h>
 
 int main(int argc, char** argv) {
-    if(argc == 1) {
+    if(argc <= 1) {
         printf("insufficient\n");
         return 0;
     }