perf top: Properly notify the user that vmlinux is missing

Before this patch this message would very briefly appear on the
screen and then the screen would get updates only on the top,
for number of interrupts received, etc, but no annotation would
be performed:

 [root@doppio linux-2.6-tip]# perf top -s n_tty_write > /tmp/bla
 objdump: '[kernel.kallsyms]': No such file

Now this is what the user gets:

 [root@doppio linux-2.6-tip]# perf top -s n_tty_write
 Can't annotate n_tty_write: No vmlinux file was found in the
 path: [0] vmlinux
 [1] /boot/vmlinux
 [2] /boot/vmlinux-2.6.33-rc5
 [3] /lib/modules/2.6.33-rc5/build/vmlinux
 [4] /usr/lib/debug/lib/modules/2.6.33-rc5/vmlinux
 [root@doppio linux-2.6-tip]#

This bug was introduced when we added automatic search for
vmlinux, before that time the user had to specify a vmlinux
file.

Reported-by: David S. Miller <davem@davemloft.net>
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <stable@kernel.org>
LKML-Reference: <1268664418-28328-2-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>