fix memory allocation to be portable

or as Coverity puts it:

suspicious_sizeof: Passing argument /* sizeof (struct ts_sample_mt **) */ to function malloc and then casting the return value to struct ts_sample_mt ** is suspicious. In this particular case sizeof (struct ts_sample_mt **) happens to be equal to sizeof (struct ts_sample_mt *), but this is not a portable assumption.

plugins/input-raw.c

@@ -364,7 +364,7 @@ static int ts_input_read_mt(struct tslib_module_info *inf,
 	int pen_up = 0;
 
 	if (i->buf == NULL) {
-		i->buf = malloc(nr * sizeof(struct ts_sample_mt **));
+		i->buf = malloc(nr * sizeof(struct ts_sample_mt *));
 		if (!i->buf)
 			return -ENOMEM;
 

plugins/median.c

@@ -202,7 +202,7 @@ static int median_read_mt(struct tslib_module_info *inf, struct ts_sample_mt **s
 			free(c->delay_mt);
 		}
 
-		c->delay_mt = malloc(max_slots * sizeof(struct ts_sample_mt **));
+		c->delay_mt = malloc(max_slots * sizeof(struct ts_sample_mt *));
 		if (!c->delay_mt)
 			return -ENOMEM;
 

plugins/variance.c

@@ -142,7 +142,7 @@ static int variance_read_mt(struct tslib_module_info *info, struct ts_sample_mt
 	if (!samp)
 		return -ENOMEM;
 
-	cur_mt = malloc(nr * sizeof(struct ts_sample_mt **));
+	cur_mt = malloc(nr * sizeof(struct ts_sample_mt *));
 	if (!cur_mt) {
 		free(samp);
 		return -ENOMEM;

tools/ts_uinput.c

@@ -614,7 +614,7 @@ int main(int argc, char **argv)
 	if (!data.ev)
 		goto out;
 
-	data.s_array = calloc(TS_READ_WHOLE_SAMPLES, sizeof(struct ts_sample_mt **));
+	data.s_array = calloc(TS_READ_WHOLE_SAMPLES, sizeof(struct ts_sample_mt *));
 	if (!data.s_array)
 		goto out;