wifi: brcmfmac: replace one-element array with flexible-array member in struct brcmf_dload_data_le

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element array with flexible-array
member in struct brcmf_dload_data_le.

Important to mention is that doing a build before/after this patch results
in no binary output differences.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines
on memcpy() and help us make progress towards globally enabling
-fstrict-flex-arrays=3 [1].

Link: https://github.com/KSPP/linux/issues/230
Link: https://github.com/KSPP/linux/issues/79
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/905f5b68cf93c812360d081caae5b15221db09b6.1668548907.git.gustavoars@kernel.org

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

@@ -110,7 +110,7 @@ static int brcmf_c_download(struct brcmf_if *ifp, u16 flag,
 	dload_buf->dload_type = cpu_to_le16(DL_TYPE_CLM);
 	dload_buf->len = cpu_to_le32(len);
 	dload_buf->crc = cpu_to_le32(0);
-	len = sizeof(*dload_buf) + len - 1;
+	len = sizeof(*dload_buf) + len;
 
 	err = brcmf_fil_iovar_data_set(ifp, "clmload", dload_buf, len);
 
@@ -139,7 +139,7 @@ static int brcmf_c_process_clm_blob(struct brcmf_if *ifp)
 		return 0;
 	}
 
-	chunk_buf = kzalloc(sizeof(*chunk_buf) + MAX_CHUNK_LEN - 1, GFP_KERNEL);
+	chunk_buf = kzalloc(sizeof(*chunk_buf) + MAX_CHUNK_LEN, GFP_KERNEL);
 	if (!chunk_buf) {
 		err = -ENOMEM;
 		goto done;

drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h

@@ -943,7 +943,7 @@ struct brcmf_dload_data_le {
 	__le16 dload_type;
 	__le32 len;
 	__le32 crc;
-	u8 data[1];
+	u8 data[];
 };
 
 /**