src: use namespace prefix osmo_counter*

Summary of changes:

s/struct counter/struct osmo_counter/g
s/counter_inc/osmo_counter_inc/g
s/counter_get/osmo_counter_get/g
s/counter_reset/osmo_counter_reset/g
s/counter_alloc/osmo_counter_alloc/g
s/counter_free/osmo_counter_free
diff --git a/openbsc/src/libbsc/bsc_vty.c b/openbsc/src/libbsc/bsc_vty.c
index 5a4bd6e..4cd027f 100644
--- a/openbsc/src/libbsc/bsc_vty.c
+++ b/openbsc/src/libbsc/bsc_vty.c
@@ -2518,18 +2518,18 @@
 void openbsc_vty_print_statistics(struct vty *vty, struct gsm_network *net)
 {
 	vty_out(vty, "Channel Requests        : %lu total, %lu no channel%s",
-		counter_get(net->stats.chreq.total),
-		counter_get(net->stats.chreq.no_channel), VTY_NEWLINE);
+		osmo_counter_get(net->stats.chreq.total),
+		osmo_counter_get(net->stats.chreq.no_channel), VTY_NEWLINE);
 	vty_out(vty, "Channel Failures        : %lu rf_failures, %lu rll failures%s",
-		counter_get(net->stats.chan.rf_fail),
-		counter_get(net->stats.chan.rll_err), VTY_NEWLINE);
+		osmo_counter_get(net->stats.chan.rf_fail),
+		osmo_counter_get(net->stats.chan.rll_err), VTY_NEWLINE);
 	vty_out(vty, "Paging                  : %lu attempted, %lu complete, %lu expired%s",
-		counter_get(net->stats.paging.attempted),
-		counter_get(net->stats.paging.completed),
-		counter_get(net->stats.paging.expired), VTY_NEWLINE);
+		osmo_counter_get(net->stats.paging.attempted),
+		osmo_counter_get(net->stats.paging.completed),
+		osmo_counter_get(net->stats.paging.expired), VTY_NEWLINE);
 	vty_out(vty, "BTS failures            : %lu OML, %lu RSL%s",
-		counter_get(net->stats.bts.oml_fail),
-		counter_get(net->stats.bts.rsl_fail), VTY_NEWLINE);
+		osmo_counter_get(net->stats.bts.oml_fail),
+		osmo_counter_get(net->stats.bts.rsl_fail), VTY_NEWLINE);
 }
 
 DEFUN(logging_fltr_imsi,