target-cris: Fix buffer overflow

Report from smatch:

target-cris/translate.c:3464 cpu_dump_state(32) error:
 buffer overflow 'env->sregs' 4 <= 255

sregs is declared 'uint32_t sregs[4][16]', so the first index must be
less than 4 or ARRAY_SIZE(env->sregs).

Signed-off-by: Stefan Weil <sw@weilnetz.de>

target-cris/translate.c

@@ -3458,7 +3458,7 @@ void cpu_dump_state (CPUCRISState *env, FILE *f, fprintf_function cpu_fprintf,
 	}
 	srs = env->pregs[PR_SRS];
 	cpu_fprintf(f, "\nsupport function regs bank %x:\n", srs);
-	if (srs < 256) {
+	if (srs < ARRAY_SIZE(env->sregs)) {
 		for (i = 0; i < 16; i++) {
 			cpu_fprintf(f, "s%2.2d=%8.8x ",
 				    i, env->sregs[srs][i]);