libxtables: prefix/order - strtoui

This commit also throws out the redundant string_to_number_*.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/extensions/libipt_icmp.c b/extensions/libipt_icmp.c
index 7aff9ca..de4c338 100644
--- a/extensions/libipt_icmp.c
+++ b/extensions/libipt_icmp.c
@@ -147,12 +147,12 @@
 		if (slash)
 			*slash = '\0';
 
-		if (string_to_number(buffer, 0, UINT8_MAX, &number) == -1)
+		if (!xtables_strtoui(buffer, NULL, &number, 0, UINT8_MAX))
 			exit_error(PARAMETER_PROBLEM,
 				   "Invalid ICMP type `%s'\n", buffer);
 		*type = number;
 		if (slash) {
-			if (string_to_number(slash+1, 0, UINT8_MAX, &number) == -1)
+			if (!xtables_strtoui(slash+1, NULL, &number, 0, UINT8_MAX))
 				exit_error(PARAMETER_PROBLEM,
 					   "Invalid ICMP code `%s'\n",
 					   slash+1);