ART: Fix debug output for bad reused MemMap.

Log the error_msg instead of a pointer to it.
Raise the log level to ERROR for the process maps.

(cherry picked from commit b5505823ad3d0bab8fc9c15c266a3d8cd96ee59e)

Change-Id: Ib0c258961e2384125907aca4bae2108f36067d5f
diff --git a/runtime/mem_map.cc b/runtime/mem_map.cc
index 959bb75..a5f7341 100644
--- a/runtime/mem_map.cc
+++ b/runtime/mem_map.cc
@@ -153,7 +153,7 @@
       return true;
     }
   }
-  PrintFileToLog("/proc/self/maps", LogSeverity::WARNING);
+  PrintFileToLog("/proc/self/maps", LogSeverity::ERROR);
   *error_msg = StringPrintf("Requested region 0x%08" PRIxPTR "-0x%08" PRIxPTR " does not overlap "
                             "any existing map. See process maps in the log.", begin, end);
   return false;
@@ -256,7 +256,7 @@
     // Only use this if you actually made the page reservation yourself.
     CHECK(expected_ptr != nullptr);
 
-    DCHECK(ContainedWithinExistingMap(expected_ptr, byte_count, error_msg)) << error_msg;
+    DCHECK(ContainedWithinExistingMap(expected_ptr, byte_count, error_msg)) << *error_msg;
     flags |= MAP_FIXED;
   }
 
@@ -411,7 +411,7 @@
     // Only use this if you actually made the page reservation yourself.
     CHECK(expected_ptr != nullptr);
 
-    DCHECK(ContainedWithinExistingMap(expected_ptr, byte_count, error_msg)) << error_msg;
+    DCHECK(ContainedWithinExistingMap(expected_ptr, byte_count, error_msg)) << *error_msg;
     flags |= MAP_FIXED;
   } else {
     CHECK_EQ(0, flags & MAP_FIXED);