libpower: log errors to logcat

Bug: n/a
Test: failure to open /sys/power/wake_lock is now recorded in logcat
Change-Id: Ifb390888d0e83b411295a35a3addbef604c930d0

power.c

@@ -57,7 +57,7 @@ open_file_descriptors(const char * const paths[])
         int fd = open(paths[i], O_RDWR | O_CLOEXEC);
         if (fd < 0) {
             g_error = -errno;
-            fprintf(stderr, "fatal error opening \"%s\": %s\n", paths[i],
+            ALOGE("fatal error opening \"%s\": %s\n", paths[i],
                 strerror(errno));
             return -1;
         }