pdump: fix created directory permissions

pdump: fix created directory permissions

Inside the function pdump_get_socket_path(), pdump socket
directories are created using mkdir() call with permissions 700,
which was assigning wrong permissions to the directories
i.e. "d-w-r-xr-T" instead of drwx---. The reason is mkdir() call
doesn't consider 700 as an octal value until unless 0 is explicitly
added before the value. Because of this, socket creation failure is
observed when DPDK application was ran in non root user mode.
DPDK application running in root user mode never reported the issue.

So 0 is prefixed to the value to create directories with
the correct permissions.

Fixes: e4ffa2d3 ("pdump: fix error handlings")
Fixes: bdd8dcc6 ("pdump: fix default socket path")

Reported-by: Jianfeng Tan <jianfeng.tan@intel.com>
Signed-off-by: Reshma Pattan <reshma.pattan@intel.com>
Acked-by: Remy Horton <remy.horton@intel.com>