BuildSystem: Fix a few issues hightlighted by gcc 6.x

gcc 6.1.1 caught a few more issues.
Made sure the unit tests still pass for the func_env and stdtime
issues.

ASTERISK-26157 #close

Change-Id: I6664d8f34a45bc1481d2a854481c7878b0c1cf8e

channels/chan_unistim.c

@@ -567,8 +567,10 @@ static const unsigned char packet_send_stream_based_tone_off[] =
 	{ 0x16, 0x05, 0x1c, 0x00, 0x00 };
 
 static const unsigned char packet_send_mute[] = { 0x16, 0x05, 0x04, 0x00, 0x00 };
+#ifdef NOT_USED
 static const unsigned char packet_send_CloseAudioStreamRX[] = { 0x16, 0x05, 0x31, 0x00, 0xff };
 static const unsigned char packet_send_CloseAudioStreamTX[] = { 0x16, 0x05, 0x31, 0xff, 0x00 };
+#endif
 static const unsigned char packet_send_stream_based_tone_on[] =
 	{ 0x16, 0x06, 0x1b, 0x00, 0x00, 0x05 };
 static const unsigned char packet_send_stream_based_tone_single_freq[] =

funcs/func_env.c

@@ -624,7 +624,7 @@ static int file_read(struct ast_channel *chan, const char *cmd, char *data, stru
 				ast_log(LOG_ERROR, "Cannot seek to offset %" PRId64 ": %s\n", i, strerror(errno));
 			}
 			end = fread(fbuf, 1, sizeof(fbuf), ff);
-			for (pos = (end < sizeof(fbuf) ? fbuf + end - 1 : fbuf + sizeof(fbuf) - 1); pos > fbuf - 1; pos--) {
+			for (pos = (end < sizeof(fbuf) ? fbuf + end - 1 : fbuf + sizeof(fbuf) - 1); pos >= fbuf; pos--) {
 				LINE_COUNTER(pos, format, count);
 
 				if (length < 0 && count * -1 == length) {
@@ -1024,7 +1024,7 @@ static int file_write(struct ast_channel *chan, const char *cmd, char *data, con
 						fclose(ff);
 						return -1;
 					}
-					for (pos = fbuf + sizeof(fbuf) - 1; pos > fbuf - 1; pos--) {
+					for (pos = fbuf + sizeof(fbuf) - 1; pos >= fbuf; pos--) {
 						LINE_COUNTER(pos, newline_format, count);
 
 						if (length < 0 && count * -1 == length) {

main/say.c

@@ -5774,13 +5774,14 @@ int ast_say_date_with_format_it(struct ast_channel *chan, time_t t, const char *
 			case 'I':
 			case 'l':
 				/* 12-Hour */
-				if (tm.tm_hour == 0)
+				if (tm.tm_hour == 0) {
 					ast_copy_string(nextmsg, "digits/12", sizeof(nextmsg));
-				else if (tm.tm_hour > 12)
+				} else if (tm.tm_hour > 12) {
 					snprintf(nextmsg, sizeof(nextmsg), "digits/%d", tm.tm_hour - 12);
-				else
+				} else {
 					snprintf(nextmsg, sizeof(nextmsg), "digits/%d", tm.tm_hour);
-					res = wait_file(chan, ints, nextmsg, lang);
+				}
+				res = wait_file(chan, ints, nextmsg, lang);
 				break;
 			case 'H':
 			case 'k':
@@ -5800,11 +5801,12 @@ int ast_say_date_with_format_it(struct ast_channel *chan, time_t t, const char *
 			case 'P':
 			case 'p':
 				/* AM/PM */
-				if (tm.tm_hour > 11)
+				if (tm.tm_hour > 11) {
 					ast_copy_string(nextmsg, "digits/p-m", sizeof(nextmsg));
-				else
+				} else {
 					ast_copy_string(nextmsg, "digits/a-m", sizeof(nextmsg));
-					res = wait_file(chan, ints, nextmsg, lang);
+				}
+				res = wait_file(chan, ints, nextmsg, lang);
 				break;
 			case 'Q':
 				/* Shorthand for "Today", "Yesterday", or ABdY */

main/stdtime/localtime.c

@@ -1849,13 +1849,14 @@ void ast_get_dst_info(const time_t * const timep, int *dst_enabled, time_t *dst_
 		*dst_enabled = 0;
 		/* Find where I can get gmtoff */
 		i = 0;
-		while (sp->ttis[i].tt_isdst)
+		while (sp->ttis[i].tt_isdst) {
 			if (++i >= sp->typecnt) {
-			i = 0;
-			break;
+				i = 0;
+				break;
 			}
-			*gmt_off = sp->ttis[i].tt_gmtoff;
-			return;
+		}
+		*gmt_off = sp->ttis[i].tt_gmtoff;
+		return;
 	}
 
 	for (i = 1; i < sp->timecnt; ++i) {