teckpack: codecs: Use scnprintf() for robustness

Reasoning explained here torvalds/linux@0623682

Also fixes this warning:
../techpack/audio/asoc/codecs/wcd-clsh.c:73:9: warning: ‘snprintf’ argument 4 overlaps destination object ‘buf’ [-Wrestrict]
   73 |   cnt = snprintf(buf, buflen - cnt - 1, "%s%s%s", buf,
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   74 |           buf[0] == '\0' ? "[" : "|",
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~
   75 |           states[i]);
      |

Signed-off-by: Yaroslav Furman <yaro330@gmail.com>
Signed-off-by: Adam W. Willis <return.of.octobot@gmail.com>
Signed-off-by: CloudedQuartz <ravenklawasd@gmail.com>

techpack/audio/asoc/codecs/wcd-clsh.c

@@ -70,7 +70,7 @@ static const char *state_to_str(u8 state, char *buf, size_t buflen)
 	for (i = 0; i < ARRAY_SIZE(states); i++) {
 		if (!(state & (1 << i)))
 			continue;
-		cnt = snprintf(buf, buflen - cnt - 1, "%s%s%s", buf,
+		cnt = scnprintf(buf, buflen - cnt - 1, "%s%s%s", buf,
 			       buf[0] == '\0' ? "[" : "|",
 			       states[i]);
 	}

techpack/audio/asoc/codecs/wcd9xxx-common-v2.c

@@ -365,7 +365,7 @@ static const char *state_to_str(u8 state, char *buf, size_t buflen)
 	for (i = 0; i < ARRAY_SIZE(states); i++) {
 		if (!(state & (1 << i)))
 			continue;
-		cnt = snprintf(buf, buflen - cnt - 1, "%s%s%s", buf,
+		cnt = scnprintf(buf, buflen - cnt - 1, "%s%s%s", buf,
 			       buf[0] == '\0' ? "[" : "|",
 			       states[i]);
 	}