audit: always follow va_copy() with va_end()

A call to va_copy() should always be followed by a call to va_end() in
the same function.  In kernel/autit.c::audit_log_vformat() this is not
always done.  This patch makes sure va_end() is always called.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>