lib/, src/: str2*(): Rename functions and reorder parameters

This makes them compatible with liba2i's functions.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

src/lastlog.c

@@ -328,7 +328,7 @@ int main (int argc, char **argv)
 			case 'b':
 			{
 				unsigned long inverse_days;
-				if (getulong(optarg, &inverse_days) == -1) {
+				if (str2ul(&inverse_days, optarg) == -1) {
 					fprintf (stderr,
 					         _("%s: invalid numeric argument '%s'\n"),
 					         Prog, optarg);
@@ -356,7 +356,7 @@ int main (int argc, char **argv)
 			case 't':
 			{
 				unsigned long days;
-				if (getulong(optarg, &days) == -1) {
+				if (str2ul(&days, optarg) == -1) {
 					fprintf (stderr,
 					         _("%s: invalid numeric argument '%s'\n"),
 					         Prog, optarg);