Fix build for GCC 10.2.1

--- ./dpid/dpid.h
+++ ./dpid/dpid.h
@@ -25,10 +25,10 @@
 
 /*! \TODO: Should read this from dillorc */
 #define SRS_NAME "dpid.srs"
-char *srs_name;
+extern char *srs_name;
 
 /*! dpid's service request socket file descriptor */
-int srs_fd;
+extern int srs_fd;
 
 /*! plugin state information
  */
@@ -49,19 +49,19 @@ struct service {
 };
 
 /*! Number of available plugins */
-int numdpis;
+extern int numdpis;
 
 /*! Number of sockets being watched */
-int numsocks;
+extern int numsocks;
 
 /*! State information for each plugin. */
-struct dp *dpi_attr_list;
+extern struct dp *dpi_attr_list;
 
 /*! service served for each plugin  */
-Dlist *services_list;
+extern Dlist *services_list;
 
 /*! Set of sockets watched for connections */
-fd_set sock_set;
+extern fd_set sock_set;
 
 /*! Set to 1 by the SIGCHLD handler dpi_sigchld */
 extern volatile sig_atomic_t caught_sigchld;
--- ./dpid/dpid_common.h
+++ ./dpid/dpid_common.h
@@ -38,10 +38,10 @@
 
 
 /*! Error codes for dpid */
-enum {
+typedef enum {
    no_errors,
    dpid_srs_addrinuse /* dpid service request socket address already in use */
-} dpi_errno;
+} dpi_errno_t;
 
 /*! Intended for identifying dillo plugins
  * and related files
--- ./dpid/main.c
+++ ./dpid/main.c
@@ -33,6 +33,27 @@
 sigset_t mask_sigchld;
 
 
+/*! Number of available plugins */
+int numdpis;
+
+/*! Number of sockets being watched */
+int numsocks;
+
+/*! State information for each plugin. */
+struct dp *dpi_attr_list;
+
+/*! service served for each plugin  */
+Dlist *services_list;
+
+/*! Set of sockets watched for connections */
+fd_set sock_set;
+
+/*! dpid's service request socket file name */
+char *srs_name;
+
+/*! dpid's service request socket file descriptor */
+int srs_fd;
+
 /* Start a dpi filter plugin after accepting the pending connection
  * \Return
  * \li Child process ID on success
@@ -210,6 +231,7 @@ int main(void)
    int dpid_idle_timeout = 60 * 60; /* default, in seconds */
    struct timeval select_timeout;
    sigset_t mask_none;
+   dpi_errno_t dpi_errno;
    fd_set selected_set;
 
    dpi_attr_list = NULL;