jbd2: add missing MODULE_DESCRIPTION()

Fix the 'make W=1' warning:
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/jbd2/jbd2.o

Signed-off-by: Jeff Johnson <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Theodore Ts'o <[e-mail]>

fs/jbd2/journal.c

···
 	jbd2_journal_destroy_caches();
 }
 
+MODULE_DESCRIPTION("Generic filesystem journal-writing module");
 MODULE_LICENSE("GPL");
 module_init(journal_init);
 module_exit(journal_exit);