brcmutil: use define for boardrev string function

Introducing a define that the caller of brcmu_boardrev_str() can
use to allocate enough room for buffer passed to the function.
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/brcm80211/brcmsmac/debug.c

@@ -78,7 +78,7 @@ int brcms_debugfs_hardware_read(struct seq_file *s, void *data)
 	struct brcms_hardware *hw = drvr->wlc->hw;
 	struct bcma_device *core = hw->d11core;
 	struct bcma_bus *bus = core->bus;
-	char boardrev[10];
+	char boardrev[BRCMU_BOARDREV_LEN];
 
 	seq_printf(s, "chipnum 0x%x\n"
 		   "chiprev 0x%x\n"

drivers/net/wireless/brcm80211/brcmutil/utils.c

@@ -267,10 +267,11 @@ char *brcmu_boardrev_str(u32 brev, char *buf)
 	char c;
 
 	if (brev < 0x100) {
-		snprintf(buf, 8, "%d.%d", (brev & 0xf0) >> 4, brev & 0xf);
+		snprintf(buf, BRCMU_BOARDREV_LEN, "%d.%d",
+			 (brev & 0xf0) >> 4, brev & 0xf);
 	} else {
 		c = (brev & 0xf000) == 0x1000 ? 'P' : 'A';
-		snprintf(buf, 8, "%c%03x", c, brev & 0xfff);
+		snprintf(buf, BRCMU_BOARDREV_LEN, "%c%03x", c, brev & 0xfff);
 	}
 	return buf;
 }

drivers/net/wireless/brcm80211/include/brcmu_utils.h

@@ -218,6 +218,8 @@ void brcmu_dbg_hex_dump(const void *data, size_t size, const char *fmt, ...)
 }
 #endif
 
+#define BRCMU_BOARDREV_LEN	8
+
 char *brcmu_boardrev_str(u32 brev, char *buf);
 
 #endif				/* _BRCMU_UTILS_H_ */