Logging level (#38)

* Set logging levels in Makefile using -DRAY_COMMON_LOG_LEVEL=level

* Lower level of some LOG_ERROR messages, log the name of the table operation on failure

* Address rest of Robert's comments

* Fix spurious log message

src/plasma/malloc.c

@@ -61,11 +61,11 @@ int create_buffer(int64_t size) {
     return -1;
   }
   if (unlink(file_name) != 0) {
-    LOG_ERR("unlink error");
+    LOG_ERROR("unlink error");
     return -1;
   }
   if (ftruncate(fd, (off_t) size) != 0) {
-    LOG_ERR("ftruncate error");
+    LOG_ERROR("ftruncate error");
     return -1;
   }
   return fd;
@@ -78,6 +78,7 @@ void *fake_mmap(size_t size) {
   size += sizeof(size_t);
 
   int fd = create_buffer(size);
+  CHECKM(fd >= 0, "Failed to create buffer during mmap");
   void *pointer = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
   if (pointer == MAP_FAILED) {
     return pointer;