pstore: Fix duplicate {console,ftrace}-efi entries

commit d4bf205d upstream.

The pstore filesystem still creates duplicate filename/inode pairs for
some pstore types.  Add the id to the filename to prevent that.

Before patch:

[/sys/fs/pstore] ls -li
total 0
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi

After:

[/sys/fs/pstore] ls -li
total 0
1232 -r--r--r--. 1 root root 148 Sep 29 17:09 console-efi-141202499100000
1231 -r--r--r--. 1 root root  67 Sep 29 17:09 console-efi-141202499200000
1230 -r--r--r--. 1 root root 148 Sep 29 17:44 console-efi-141202705400000
1229 -r--r--r--. 1 root root  67 Sep 29 17:44 console-efi-141202705500000
1228 -r--r--r--. 1 root root  67 Sep 29 20:42 console-efi-141203772600000
1227 -r--r--r--. 1 root root 148 Sep 29 23:42 console-efi-141204854900000
1226 -r--r--r--. 1 root root  67 Sep 29 23:42 console-efi-141204855000000
1225 -r--r--r--. 1 root root 148 Sep 29 23:59 console-efi-141204954200000
1224 -r--r--r--. 1 root root  67 Sep 29 23:59 console-efi-141204954400000
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

fs/pstore/inode.c

@@ -320,10 +320,10 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
 						compressed ? ".enc.z" : "");
 		break;
 	case PSTORE_TYPE_CONSOLE:
-		sprintf(name, "console-%s", psname);
+		sprintf(name, "console-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_FTRACE:
-		sprintf(name, "ftrace-%s", psname);
+		sprintf(name, "ftrace-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_MCE:
 		sprintf(name, "mce-%s-%lld", psname, id);