Revert "Copy structs using assignment, not memcpy()."

This reverts commit d1965788249d7e22cdde4021d452cf0dc6c6b9bd.

This breaks my build on Gentoo running gcc 4.9.2

libgps_shm.c: In function 'int gps_shm_read(gps_data_t*)':
libgps_shm.c:122:12: error: no match for 'operator=' (operand types are
'gps_data_t' and 'volatile gps_data_t')
  noclobber = shared->gpsdata;
            ^
libgps_shm.c:122:12: note: candidate is:
In file included from gpsd.h:350:0,
                 from libgps_shm.c:30:
gps.h:1918:8: note: gps_data_t& gps_data_t::operator=(const gps_data_t&)
 struct gps_data_t {
        ^
gps.h:1918:8: note:   no known conversion for argument 1 from 'volatile
gps_data_t' to 'const gps_data_t&'

1 files changed, 1 insertions, 1 deletions

diff --git a/gpsd.c b/gpsd.c
index 3154bfd7..ace2ed6c 100644
--- a/gpsd.c
+++ b/gpsd.c
@@ -1747,7 +1747,7 @@ static void netgnss_autoconnect(struct gps_context_t *context,
 		    && (tp == NULL || hold.dist > tp->dist))
 		    tp = sp;
 	    if (tp != NULL)
-		*tp = hold;
+		memcpy(tp, &hold, sizeof(struct dgps_server_t));
 	}
     }
     (void)fclose(sfp);