undo some hunks that were removed by mistake

kern/emu/mm.c

@@ -55,6 +55,8 @@ grub_realloc (void *ptr, grub_size_t size)
 {
   void *ret;
   ret = realloc (ptr, size);
+  if (!ret)
+    grub_error (GRUB_ERR_OUT_OF_MEMORY, "out of memory");
   return ret;
 }
 
@@ -76,5 +78,8 @@ grub_memalign (grub_size_t align, grub_size_t size)
   grub_util_error ("grub_memalign is not supported");
 #endif
 
+  if (!p)
+    grub_error (GRUB_ERR_OUT_OF_MEMORY, "out of memory");
+
   return p;
 }