RRO: idmap: allow flock(2) to block

During creation of an idmap an advisory lock is applied on the
output file using flock(2). This commit removes the LOCK_NB flag
from the call to flock(2).

The reason for this is that if the function were to return
EWOULDBLOCK, the entire idmap operation would be aborted leading
to the device booting without the correct overlay packages applied.

Change-Id: Iad319779976e950d4354e4f60b30439f6f208b77
diff --git a/cmds/idmap/create.cpp b/cmds/idmap/create.cpp
index 41395f1..9d60ee1 100644
--- a/cmds/idmap/create.cpp
+++ b/cmds/idmap/create.cpp
@@ -41,7 +41,7 @@
             ALOGD("error: fchmod %s: %s\n", path, strerror(errno));
             goto fail;
         }
-        if (TEMP_FAILURE_RETRY(flock(fd, LOCK_EX | LOCK_NB)) != 0) {
+        if (TEMP_FAILURE_RETRY(flock(fd, LOCK_EX)) != 0) {
             ALOGD("error: flock %s: %s\n", path, strerror(errno));
             goto fail;
         }