Fix a regression introduced by my previous commit, ram_size is now
unsigned.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4266 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/vl.c b/vl.c
index 2b6e459..c30a87f 100644
--- a/vl.c
+++ b/vl.c
@@ -8277,7 +8277,7 @@
     machine = first_machine;
     cpu_model = NULL;
     initrd_filename = NULL;
-    ram_size = -1;
+    ram_size = 0;
     vga_ram_size = VGA_RAM_SIZE;
 #ifdef CONFIG_GDBSTUB
     use_gdbstub = 0;
@@ -9000,7 +9000,7 @@
         } else
             ram_size = phys_ram_size;
     } else {
-        if (ram_size < 0)
+        if (ram_size == 0)
             ram_size = DEFAULT_RAM_SIZE * 1024 * 1024;
 
         phys_ram_size += ram_size;