ALSA: cs46xx: Potential NULL dereference in probe

BugLink: https://bugs.launchpad.net/bugs/1811647

commit 1524f4e4 upstream.

The "chip->dsp_spos_instance" can be NULL on some of the ealier error
paths in snd_cs46xx_create().
Reported-by: "Yavuz, Tuba" <tuba@ece.ufl.edu>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

sound/pci/cs46xx/dsp_spos.c

@@ -899,6 +899,9 @@ int cs46xx_dsp_proc_done (struct snd_cs46xx *chip)
 	struct dsp_spos_instance * ins = chip->dsp_spos_instance;
 	int i;
 
+	if (!ins)
+		return 0;
+
 	snd_info_free_entry(ins->proc_sym_info_entry);
 	ins->proc_sym_info_entry = NULL;