scsi: snic: debugfs: remove local storage of debugfs files

There is no need to keep the dentry around for the debugfs trace files,
as we can just look it up when we want to remove it later on. Simplify
the structure by removing the dentries and relying on debugfs to find
the dentry to remove when we want to.

By doing this change, we remove the last in-kernel user that was storing
the result of debugfs_create_bool(), so that api can be cleaned up.

Cc: Karan Tilak Kumar <[e-mail]>
Cc: Sesidhar Baddela <[e-mail]>
Cc: "James E.J. Bottomley" <[e-mail]>
Cc: "Martin K. Petersen" <[e-mail]>
Cc: <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/scsi/snic/snic_debugfs.c

···
 
 DEFINE_SEQ_ATTRIBUTE(snic_trc);
 
+#define TRC_ENABLE_FILE	"tracing_enable"
+#define TRC_FILE	"trace"
 /*
  * snic_trc_debugfs_init : creates trace/tracing_enable files for trace
  * under debugfs
  */
 void snic_trc_debugfs_init(void)
 {
-	snic_glob->trc.trc_enable = debugfs_create_bool("tracing_enable",
-							S_IFREG | S_IRUGO | S_IWUSR,
-							snic_glob->trc_root,
-							&snic_glob->trc.enable);
+	debugfs_create_bool(TRC_ENABLE_FILE, S_IFREG | S_IRUGO | S_IWUSR,
+			    snic_glob->trc_root, &snic_glob->trc.enable);
 
-	snic_glob->trc.trc_file = debugfs_create_file("trace",
-						      S_IFREG | S_IRUGO | S_IWUSR,
-						      snic_glob->trc_root, NULL,
-						      &snic_trc_fops);
+	debugfs_create_file(TRC_FILE, S_IFREG | S_IRUGO | S_IWUSR,
+			    snic_glob->trc_root, NULL, &snic_trc_fops);
 }
 
 /*
···
 void
 snic_trc_debugfs_term(void)
 {
-	debugfs_remove(snic_glob->trc.trc_file);
-	snic_glob->trc.trc_file = NULL;
-
-	debugfs_remove(snic_glob->trc.trc_enable);
-	snic_glob->trc.trc_enable = NULL;
+	debugfs_remove(debugfs_lookup(TRC_FILE, snic_glob->trc_root));
+	debugfs_remove(debugfs_lookup(TRC_ENABLE_FILE, snic_glob->trc_root));
 }

drivers/scsi/snic/snic_trc.h

···
 	u32	rd_idx;
 	u32	wr_idx;
 	bool	enable;			/* Control Variable for Tracing */
-
-	struct dentry *trc_enable;	/* debugfs file object */
-	struct dentry *trc_file;
 };
 
 int snic_trc_init(void);