fix format specifier in libpkg, which triggers a coredump

[op]

Summary

commit f6c84ecd8a30a77eeefd8106496e6692d6348190
Author: Oliver Pinter <[e-mail]>
Date: Thu Aug 6 01:35:47 2015 +0200

HBSD: fix format specifier in libpkg's pkg_vets(...)

The attr variables type is int, but the format string in pkg_emit_error
is %s. In some case with enabled ASLR this cause a core dump.

 441     {
 442             int attr;
 443
 444             while ((attr = va_arg(ap, int)) > 0) {
 445                     if (attr >= PKG_NUM_FIELDS || attr <= 0) {
 446                             pkg_emit_error("Bad argument on pkg_set %s", attr);
 447                             return (EPKG_FATAL);
 448                     }
 449
 450                     switch (attr) {

(gdb) bt
 #0  0x00000000007f25ab in strlen ()
 #1  0x00000000007e8062 in __vfprintf ()
 #2  0x00000000007a5747 in vasprintf_l ()
 #3  0x0000000000451e7e in pkg_emit_error (
    fmt=0x84b9f5 "Bad argument on pkg_set %s") at pkg_event.c:418
 #4  0x00000000004264c9 in pkg_vset (pkg=0x22036461600, ap=0x6529128ac3e0)
    at pkg.c:446
 #5  0x0000000000426409 in pkg_set2 (pkg=0x22036461600) at pkg.c:567
 #6  0x00000000004024a2 in exec_audit (argc=1, argv=0x6529128acd00)
    at audit.c:207
 #7  0x000000000040e22e in main (argc=2, argv=0x6529128accf8) at main.c:847

Sponsored-by: HardenedBSD
Found-by: ASLR - stack randomization
Signed-off-by: Oliver Pinter <[e-mail]>
CC: Pedro Giffuni <[e-mail]
CC: Baptiste Daroussin <[e-mail]>

[op]

And created a pull request in github too: https://github.com/freebsd/pkg/pull/1302

[bapt]

This is in pkg master and release 1.5.6