brcmfmac: treat NULL character in NVRAM as separator

Platform NVRAM (stored on a flash partition) has entries separated by a
NULL (\0) char. Our parsing code switches from VALUE state to IDLE
whenever it meets a NULL (\0). When that happens our IDLE handler should
simply consume it and analyze whatever is placed ahead.

This fixes harmless warnings spamming debugging output:
[  155.165624] brcmfmac: brcmf_nvram_handle_idle warning: ln=1:col=20: ignoring invalid character
[  155.180806] brcmfmac: brcmf_nvram_handle_idle warning: ln=1:col=44: ignoring invalid character
[  155.195971] brcmfmac: brcmf_nvram_handle_idle warning: ln=1:col=63: ignoring invalid character

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c

@@ -93,7 +93,7 @@ static enum nvram_parser_state brcmf_nvram_handle_idle(struct nvram_parser *nvp)
 	c = nvp->data[nvp->pos];
 	if (c == '\n')
 		return COMMENT;
-	if (is_whitespace(c))
+	if (is_whitespace(c) || c == '\0')
 		goto proceed;
 	if (c == '#')
 		return COMMENT;