staging: brcm80211: reorg brcms_c_validboardtype for clarity

The structure of the function made it difficult to understand, so reorganize it
to make it clearer.
Reported-by: Greg Dietsche <Gregory.Dietsche@cuw.edu>
Signed-off-by: Henry Ptasinski <henryp@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/brcm80211/brcmsmac/bmac.c

@@ -1905,28 +1905,33 @@ static bool brcms_c_isgoodchip(struct brcms_c_hw_info *wlc_hw)
 	return true;
 }
 
+/* Validate some board info parameters */
 static bool brcms_c_validboardtype(struct brcms_c_hw_info *wlc_hw)
 {
-	bool goodboard = true;
 	uint boardrev = wlc_hw->boardrev;
 
-	if (boardrev == 0)
-		goodboard = false;
-	else if (boardrev > 0xff) {
+	/* 4 bits each for board type, major, minor, and tiny version */
 	uint brt = (boardrev & 0xf000) >> 12;
 	uint b0 = (boardrev & 0xf00) >> 8;
 	uint b1 = (boardrev & 0xf0) >> 4;
 	uint b2 = boardrev & 0xf;
 
+	/* voards from other vendors are always considered valid */
+	if (wlc_hw->sih->boardvendor != PCI_VENDOR_ID_BROADCOM)
+		return true;
+
+	/* do some boardrev sanity checks when boardvendor is Broadcom */
+	if (boardrev == 0)
+		return false;
+
+	if (boardrev <= 0xff)
+		return true;
+
 	if ((brt > 2) || (brt == 0) || (b0 > 9) || (b0 == 0) || (b1 > 9)
 		|| (b2 > 9))
-			goodboard = false;
-	}
-
-	if (wlc_hw->sih->boardvendor != PCI_VENDOR_ID_BROADCOM)
-		return goodboard;
+		return false;
 
-	return goodboard;
+	return true;
 }
 
 static char *brcms_c_get_macaddr(struct brcms_c_hw_info *wlc_hw)