fix current position of pointer

Author: jalvesz

src/stdlib_str2num.fypp

@@ -109,7 +109,7 @@ module stdlib_str2num
         integer(int8) :: err
         !----------------------------------------------
         call to_num_base(s,v,p,err)
-        p = min( p , len(s, kind = int8) )
+        p = min( p , len(s) )
         s => s(p:)
         if(present(stat)) stat = err
     end function