retval(1): fix style

retval/retval.c

@@ -3,22 +3,22 @@
 #include <stdlib.h> /* strtol(3) */
 #include <sysexits.h> /* EX_USAGE */
 
-int usage(char *s){
-	fprintf(stderr, "Usage: %s [status]\n", s == NULL ? "retval" : s);
-	return EX_USAGE;
-}
+char *program_name = "retval";
 
 int main(int argc, char *argv[]){
 
 	switch(argc){
-		case 2: { unsigned int s;
-			errno = 0;
-			s = strtol(argv[1], &argv[1], 10);
-			if(*argv[1] != '\0' || errno != 0){
-				return usage(argv[0]);
-			}
-			return s;
-		}
-		default: return usage(argv[0]);
+		case 2: {
+				unsigned int s;
+
+				errno = 0;
+				s = strtol(argv[1], &argv[1], 10);
+
+				if(*argv[1] == '\0' && errno == 0) { return s; }
+		} /* FALLTHROUGH */
+		default:
+			fprintf(stderr, "Usage: %s status\n",
+				argv[0] == NULL ? program_name : argv[0]);
+			return EX_USAGE;
 	}
 }