exfat: Downgrade ENAMETOOLONG error message to debug messages

The ENAMETOOLONG error message is printed at each time when user tries
to operate with a too long name, and this can flood the kernel logs
easily, as every user can trigger this.  Let's downgrade this error
message level to a debug message for suppressing the superfluous
logs.

BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1201725Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

fs/exfat/nls.c

@@ -509,7 +509,7 @@ static int exfat_utf8_to_utf16(struct super_block *sb,
 	}
 
 	if (unilen > MAX_NAME_LENGTH) {
-		exfat_err(sb, "failed to %s (estr:ENAMETOOLONG) nls len : %d, unilen : %d > %d",
+		exfat_debug(sb, "failed to %s (estr:ENAMETOOLONG) nls len : %d, unilen : %d > %d",
 			  __func__, len, unilen, MAX_NAME_LENGTH);
 		return -ENAMETOOLONG;
 	}