mfi(4)/mrsas(4): Set sysctl name for driver versions consistently

Instead of printing the driver version over and over again if multiple
controllers are used, set a sysctl name for the used driver version.

Approved by:	imp, ziaee
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D56110

sys/dev/mfi/mfi.c

@@ -371,9 +371,6 @@ mfi_attach(struct mfi_softc *sc)
 	if (sc == NULL)
 		return EINVAL;
 
-	device_printf(sc->mfi_dev, "LSI MegaRAID SAS driver version: %s\n",
-	    MEGASAS_VERSION);
-
 	mtx_init(&sc->mfi_io_lock, "MFI I/O lock", NULL, MTX_DEF);
 	sx_init(&sc->mfi_config_lock, "MFI config");
 	TAILQ_INIT(&sc->mfi_ld_tqh);
@@ -764,6 +761,10 @@ mfi_attach(struct mfi_softc *sc)
 		    sc->mfi_cdev, "%s", "megaraid_sas_ioctl_node");
 	if (sc->mfi_cdev != NULL)
 		sc->mfi_cdev->si_drv1 = sc;
+	SYSCTL_ADD_STRING(device_get_sysctl_ctx(sc->mfi_dev),
+	    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->mfi_dev)),
+	    OID_AUTO, "driver_version", CTLFLAG_RD, MEGASAS_VERSION,
+	    strlen(MEGASAS_VERSION), "driver version");
 	SYSCTL_ADD_INT(device_get_sysctl_ctx(sc->mfi_dev),
 	    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->mfi_dev)),
 	    OID_AUTO, "delete_busy_volumes", CTLFLAG_RW,

sys/dev/mrsas/mrsas.c

@@ -824,9 +824,6 @@ mrsas_attach(device_t dev)
 	struct mrsas_softc *sc = device_get_softc(dev);
 	uint32_t cmd, error;
 
-	device_printf(dev, "AVAGO MegaRAID SAS driver version: %s\n",
-		MRSAS_VERSION);
-
 	memset(sc, 0, sizeof(struct mrsas_softc));
 
 	/* Look up our softc and initialize its fields. */