Fixing an unused-variable warning in microdump_writer.cc

src/client/linux/microdump_writer/microdump_writer.cc

 // Copyright (c) 2014, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 486 matching lines @@
 
       size_t next = NextOrderedMapping(mappings, curr);
       if (next == std::numeric_limits<size_t>::max())
         break;
 
       uintptr_t hole_lo = mappings[curr]->start_addr + mappings[curr]->size;
       uintptr_t hole_hi = mappings[next]->start_addr;
 
       if (hole_hi > hole_lo) {
         size_t hole_sz = hole_hi - hole_lo;
-        int log2_hole_sz = Log2Floor(hole_sz);
         hole_sum += hole_sz;
         hole_max = std::max(hole_sz, hole_max);
         ++hole_cnt;
         ++hole_histogram[Log2Floor(hole_sz)];
       }
       curr = next;
     }
 
     uintptr_t hi_addr = mappings[curr]->start_addr + mappings[curr]->size;
 
@@ skipping 72 matching lines @@
     dumper.set_crash_signal(context->siginfo.si_signo);
     dumper.set_crash_thread(context->tid);
   }
   MicrodumpWriter writer(context, mappings, microdump_extra_info, &dumper);
   if (!writer.Init())
     return false;
   return writer.Dump();
 }
 
 }  // namespace google_breakpad