cifs: fix static checker warning

Remove unnecessary NULL check of oparam->cifs_sb when parsing symlink
error response as it's already set by all smb2_open_file() callers and
deferenced earlier.

This fixes below report:

fs/cifs/smb2file.c:126 smb2_open_file()
warn: variable dereferenced before check 'oparms->cifs_sb' (see line 112)

Link: https://lore.kernel.org/r/Y0kt42j2tdpYakRu@kili
Reported-by: Dan Carpenter <[e-mail]>
Signed-off-by: Paulo Alcantara (SUSE) <[e-mail]>
Signed-off-by: Steve French <[e-mail]>

fs/cifs/smb2file.c

···
 
 		if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER))
 			rc = -ENOMEM;
-		else if (hdr->Status == STATUS_STOPPED_ON_SYMLINK && oparms->cifs_sb) {
+		else if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) {
 			rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov,
 							 &data->symlink_target);
 			if (!rc) {