fixed looping bug in conversion function

src/convert.c

@@ -63,7 +63,7 @@ char* ltoa(long number, char* string, int base)
         *string++ = '-';
     }
     
-    itoa(number, string, base);
+    ultoa(number, string, base);
     return old_string;
 }
 

src/kernel.c

@@ -12,6 +12,7 @@ void main()
     char buffer[1024];
 
     uart_init();
+    
     print_clippy();
     uart_puts("Boot successful! \n");
     uart_puts("Started execution at 0x");