regulator: dbx500: Remove unused debugfs goto label

The following build warning is seen after commit 8bdaa43808b7 ("regulator:
dbx500: no need to check return value of debugfs_create functions"):

drivers/regulator/dbx500-prcmu.c:144:1: warning: label 'exit_no_debugfs' defined but not used [-Wunused-label]

Remove the unused label and its associated error message.

Fixes: 8bdaa43808b7 ("regulator: dbx500: no need to check return value of debugfs_create functions")
Reported-by: Olof's autobuilder <[e-mail]>
Signed-off-by: Fabio Estevam <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/dbx500-prcmu.c

···
 	kfree(rdebug.state_before_suspend);
 exit_destroy_power_state:
 	debugfs_remove_recursive(rdebug.dir);
-exit_no_debugfs:
-	dev_err(&pdev->dev, "failed to create debugfs entries.\n");
 	return -ENOMEM;
 }