cifs: make fs_context error logging wrapper

This new helper will be used in the fs_context mount option parsing
code. It log errors both in:
* the fs_context log queue for userspace to read
* kernel printk buffer (dmesg, old behaviour)
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/fs_context.h

@@ -13,7 +13,12 @@
 #include <linux/parser.h>
 #include <linux/fs_parser.h>
 
-#define cifs_invalf(fc, fmt, ...) invalf(fc, fmt, ## __VA_ARGS__)
+/* Log errors in fs_context (new mount api) but also in dmesg (old style) */
+#define cifs_errorf(fc, fmt, ...)			\
+	do {						\
+		errorf(fc, fmt, ## __VA_ARGS__);	\
+		cifs_dbg(VFS, fmt, ## __VA_ARGS__);	\
+	} while (0)
 
 enum smb_version {
 	Smb_1 = 1,