scsi: aic7xxx: aic79xx: remove VLAs

In preparation to enabling -Wvla, remove VLAs and replace them with
fixed-length arrays instead.

The arrays fixed here, using the number of constant sections, aren't
really VLAs, but they appear so to the compiler. Replace the array sizes
with a pre-processor-level constant instead using ARRAY_SIZE.

This was prompted by https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Stephen Kitt <steve@sk2.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/aic7xxx/aic79xx_core.c

@@ -9338,9 +9338,9 @@ ahd_dumpseq(struct ahd_softc* ahd)
 static void
 ahd_loadseq(struct ahd_softc *ahd)
 {
-	struct	cs cs_table[num_critical_sections];
-	u_int	begin_set[num_critical_sections];
-	u_int	end_set[num_critical_sections];
+	struct	cs cs_table[NUM_CRITICAL_SECTIONS];
+	u_int	begin_set[NUM_CRITICAL_SECTIONS];
+	u_int	end_set[NUM_CRITICAL_SECTIONS];
 	const struct patch *cur_patch;
 	u_int	cs_count;
 	u_int	cur_cs;
@@ -9456,7 +9456,7 @@ ahd_loadseq(struct ahd_softc *ahd)
 		 * Move through the CS table until we find a CS
 		 * that might apply to this instruction.
 		 */
-		for (; cur_cs < num_critical_sections; cur_cs++) {
+		for (; cur_cs < NUM_CRITICAL_SECTIONS; cur_cs++) {
 			if (critical_sections[cur_cs].end <= i) {
 				if (begin_set[cs_count] == TRUE
 				 && end_set[cs_count] == FALSE) {

drivers/scsi/aic7xxx/aic79xx_seq.h_shipped

@@ -1186,5 +1186,4 @@ static const struct cs {
 	{ 759, 763 }
 };
 
-static const int num_critical_sections = sizeof(critical_sections)
-				       / sizeof(*critical_sections);
+#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)

drivers/scsi/aic7xxx/aic7xxx_core.c

@@ -6848,9 +6848,9 @@ ahc_dumpseq(struct ahc_softc* ahc)
 static int
 ahc_loadseq(struct ahc_softc *ahc)
 {
-	struct	cs cs_table[num_critical_sections];
-	u_int	begin_set[num_critical_sections];
-	u_int	end_set[num_critical_sections];
+	struct	cs cs_table[NUM_CRITICAL_SECTIONS];
+	u_int	begin_set[NUM_CRITICAL_SECTIONS];
+	u_int	end_set[NUM_CRITICAL_SECTIONS];
 	const struct patch *cur_patch;
 	u_int	cs_count;
 	u_int	cur_cs;
@@ -6915,7 +6915,7 @@ ahc_loadseq(struct ahc_softc *ahc)
 		 * Move through the CS table until we find a CS
 		 * that might apply to this instruction.
 		 */
-		for (; cur_cs < num_critical_sections; cur_cs++) {
+		for (; cur_cs < NUM_CRITICAL_SECTIONS; cur_cs++) {
 			if (critical_sections[cur_cs].end <= i) {
 				if (begin_set[cs_count] == TRUE
 				 && end_set[cs_count] == FALSE) {

drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped

@@ -1304,5 +1304,4 @@ static const struct cs {
 	{ 875, 877 }
 };
 
-static const int num_critical_sections = sizeof(critical_sections)
-				       / sizeof(*critical_sections);
+#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)

drivers/scsi/aic7xxx/aicasm/aicasm.c

@@ -451,8 +451,7 @@ output_code()
 	fprintf(ofile, "\n};\n\n");
 
 	fprintf(ofile,
-"static const int num_critical_sections = sizeof(critical_sections)\n"
-"				       / sizeof(*critical_sections);\n");
+	"#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)\n");
 
 	fprintf(stderr, "%s: %d instructions used\n", appname, instrcount);
 }