gprs/sgsn: rename gprs->mm_state -> gmm_state

GMM is the right term. MM state is already occupied.

Change-Id: I9cfdcf921e4ebd14a5e7ce7489ec4ce5d1f5515f
diff --git a/openbsc/src/gprs/sgsn_vty.c b/openbsc/src/gprs/sgsn_vty.c
index 246867d..85e4e91 100644
--- a/openbsc/src/gprs/sgsn_vty.c
+++ b/openbsc/src/gprs/sgsn_vty.c
@@ -485,7 +485,7 @@
 		pfx, mm->msisdn, mm->gb.tlli, mm->hlr, VTY_NEWLINE);
 	vty_out(vty, "%s  MM State: %s, Routeing Area: %u-%u-%u-%u, "
 		"Cell ID: %u%s", pfx,
-		get_value_string(gprs_mm_st_strs, mm->mm_state),
+		get_value_string(gprs_mm_st_strs, mm->gmm_state),
 		mm->ra.mcc, mm->ra.mnc, mm->ra.lac, mm->ra.rac,
 		mm->gb.cell_id, VTY_NEWLINE);