make code match comment

64c47374 · rsc · 19b42cc0 · 64c47374
--- a/sysfile.c
+++ b/sysfile.c
@@ -12,7 +12,7 @@
 // Fetch the nth word-sized system call argument as a file descriptor
 // and return both the descriptor and the corresponding struct file.
 static int
-argfd(int argno, int *pfd, struct file **pf)
+argfd(int n, int *pfd, struct file **pf)
 {
  int fd;
  struct file *f;