first check the count and then get

the next line of characters and not cause it to first get
the characters even if the count (cnt) has become 0.

Submitted by:	R Bezuidenhout <rbezuide@mikom.csir.co.za>

usr.bin/head/head.c

@@ -113,7 +113,7 @@ head(fp, cnt)
 {
 	register int ch;
 
-	while ((ch = getc(fp)) != EOF && cnt) {
+	while (cnt && (ch = getc(fp)) != EOF) {
 			if (putchar(ch) == EOF)
 				err(1, "stdout: %s", strerror(errno));
 			if (ch == '\n')