liblog: O_CLOEXEC flag on opens

(cherry pick from commit 78786da116064e6a2b7bb768e1eb77f3804eace4)

Bug: 28455828
Change-Id: Ic00101a6192aab7271cb0c3461e249a77d7f29ed
diff --git a/liblog/pmsg_reader.c b/liblog/pmsg_reader.c
index 5695e8a..f5e91c8 100644
--- a/liblog/pmsg_reader.c
+++ b/liblog/pmsg_reader.c
@@ -151,13 +151,13 @@
     memset(log_msg, 0, sizeof(*log_msg));
 
     if (transp->context.fd <= 0) {
-        int fd = open("/sys/fs/pstore/pmsg-ramoops-0", O_RDONLY);
+        int fd = open("/sys/fs/pstore/pmsg-ramoops-0", O_RDONLY | O_CLOEXEC);
 
         if (fd < 0) {
             return -errno;
         }
         if (fd == 0) { /* Argggg */
-            fd = open("/sys/fs/pstore/pmsg-ramoops-0", O_RDONLY);
+            fd = open("/sys/fs/pstore/pmsg-ramoops-0", O_RDONLY | O_CLOEXEC);
             close(0);
             if (fd < 0) {
                 return -errno;