I'm observing some problems that make it difficult to use lint(1).
I'll use vfscanf.c as an example, since most of the problems occur in
it.


1) It's incorrectly deciding that an expression is meaningless in some
   cases:

vfscanf.c(146): warning: expression has null effect

                                nread++, fp->_r--, fp->_p++;


2) All uses of va_start() and va_arg() generate warnings:

vfscanf.c(277): warning: possible pointer alignment problem
vfscanf.c(277): warning: pointer casts may be troublesome

                                *va_arg(ap, short *) = nread;


Can someone help fix these problems?