hw/audio/fmopl: fix segmentation fault

Current code allocates the memory for ENV_CURVE too late. Move
allocation to OPLOpenTable() and deallocation to OPLCloseTable().

To reproduce the bug start qemu with -soundhw adlib.

Fixes 2eea51bd01 "hw/audio/fmopl: Move ENV_CURVE to .heap to save
32KiB of .bss"

Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200324061855.5951-1-vr_qemu@t-online.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/hw/audio/fmopl.c b/hw/audio/fmopl.c
index 356d4df..8a71a56 100644
--- a/hw/audio/fmopl.c
+++ b/hw/audio/fmopl.c
@@ -627,6 +627,7 @@
 		free(AMS_TABLE);
 		return 0;
 	}
+    ENV_CURVE = g_new(int32_t, 2 * EG_ENT + 1);
 	/* make total level table */
 	for (t = 0;t < EG_ENT-1 ;t++){
 		rate = ((1<<TL_BITS)-1)/pow(10,EG_STEP*t/20);	/* dB -> voltage */
@@ -694,6 +695,7 @@
 
 static void OPLCloseTable( void )
 {
+    g_free(ENV_CURVE);
 	free(TL_TABLE);
 	free(SIN_TABLE);
 	free(AMS_TABLE);
@@ -1090,7 +1092,6 @@
 	OPL->clock = clock;
 	OPL->rate  = rate;
 	OPL->max_ch = max_ch;
-    ENV_CURVE = g_new(int32_t, 2 * EG_ENT + 1);
 	/* init grobal tables */
 	OPL_initialize(OPL);
 	/* reset chip */
@@ -1128,7 +1129,6 @@
 #endif
 	OPL_UnLockTable();
 	free(OPL);
-    g_free(ENV_CURVE);
 }
 
 /* ----------  Option handlers ----------       */