card_fs_sim: Avoid '/' in file names

... as that doesn't work if we want to create a similarly-named
file in the local file system.

Change-Id: Ib8734e2e4b81c915ab0fbd0d9b6662275b1d33d1
diff --git a/src/sim/card_fs_sim.c b/src/sim/card_fs_sim.c
index 3f541f7..55ce9af 100644
--- a/src/sim/card_fs_sim.c
+++ b/src/sim/card_fs_sim.c
@@ -431,7 +431,7 @@
 	add_df_with_ef(gsm, 0x5F33, "DF.ACeS", NULL, 0);
 	add_df_with_ef(gsm, 0x5F3C, "DF.MExE", sim_ef_in_mexe,
 			ARRAY_SIZE(sim_ef_in_mexe));
-	add_df_with_ef(gsm, 0x5F40, "DF.EIA/TIA-533", NULL, 0);
+	add_df_with_ef(gsm, 0x5F40, "DF.EIA-TIA-533", NULL, 0);
 	add_df_with_ef(gsm, 0x5F60, "DF.CTS", NULL, 0);
 	add_df_with_ef(gsm, 0x5F70, "DF.SoLSA", sim_ef_in_solsa,
 			ARRAY_SIZE(sim_ef_in_solsa));