WUtil: fix type used in sizeof in function wtokensplit (Coverity #50208 + #50209)

As pointed by Coverity, the type used to calculate the size to allocate was
not the right one. It now gets the compiler to deduce it from the variable
for which the memory is allocated.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

WINGs/string.c

@@ -103,9 +103,9 @@ void wtokensplit(char *command, char ***argv, int *argc)
 		token = wtokennext(line, &line);
 		if (token) {
 			if (count == 0)
-				*argv = wmalloc(sizeof(char **));
+				*argv = wmalloc(sizeof(**argv));
 			else
-				*argv = wrealloc(*argv, (count + 1) * sizeof(char **));
+				*argv = wrealloc(*argv, (count + 1) * sizeof(**argv));
 			(*argv)[count++] = token;
 		}
 	} while (token != NULL && line != NULL);