liblog: deal with warning messages

- Fix bug in fake_log_devices when it can not allocate memory
  failing to use the full on-stack buffer as backup.
- remove superfluous code.

Bug: 27265662
Change-Id: I97b6cca5f4ce8ecad9beb3a08353de596d6a4ad1
diff --git a/liblog/log_read.c b/liblog/log_read.c
index 1aff272..fc63d2c 100644
--- a/liblog/log_read.c
+++ b/liblog/log_read.c
@@ -503,10 +503,7 @@
     }
 
     if (logger_list->pid) {
-        n = snprintf(cp, remaining, " pid=%u", logger_list->pid);
-        n = min(n, remaining);
-        remaining -= n;
-        cp += n;
+        snprintf(cp, remaining, " pid=%u", logger_list->pid);
     }
 
     return send_log_msg(NULL, NULL, buf, len);
@@ -657,7 +654,6 @@
         preread_count = 0;
     }
 
-    ret = 0;
     while(1) {
         if (preread_count < sizeof(buf)) {
             ret = TEMP_FAILURE_RETRY(read(logger_list->sock,
@@ -834,7 +830,6 @@
         if (logger_list->pid) {
             ret = snprintf(cp, remaining, " pid=%u", logger_list->pid);
             ret = min(ret, remaining);
-            remaining -= ret;
             cp += ret;
         }
 
@@ -867,7 +862,6 @@
         logger_list->sock = sock;
     }
 
-    ret = 0;
     while(1) {
         memset(log_msg, 0, sizeof(*log_msg));