Removed snd_config_string_replace function.

Added back modified snd_config_refer_load function.
Added snd_func_private_pcm_subdevice function.
Removed the callback from the snd_sctl_build function (no more required).
Modified alsa.conf to use refer {} blocks again.
Modified card specific conf files to use new snd_func_private_pcm_subdevice function.

src/cards/EMU10K1.conf

@@ -62,7 +62,7 @@ pcm.emu10k1_rear {
 			}
 			{
 				name "EMU10K1 PCM Send Volume"
-				index = &(subdevice)
+				index { @func private_pcm_subdevice }
 				lock true
 				value [ 0 0 0 0 0 0 255 0 0 0 0 255 ]
 			}
@@ -118,13 +118,13 @@ pcm.emu10k1_center_lfe {
 			}
 			{
 				name "EMU10K1 PCM Send Volume"
-				index = &(subdevice)
+				index { @func private_pcm_subdevice }
 				lock true
 				value [ 0 0 0 0 255 0 0 0 0 255 0 0 ]
 			}
 			{
 				name "EMU10K1 PCM Send Routing"
-				index = &(subdevice)
+				index { @func private_pcm_subdevice }
 				lock true
 				value [ 0 1 2 3 6 7 0 1 6 7 0 1 ]
 			}

src/cards/SI_7018.conf

@@ -58,6 +58,7 @@ pcm.si7018_rear {
 				name "PCM Playback Volume"
 				preserve true
 				lock true
+				index { @func private_pcm_subdevice }
 				value [ 24 24 ]
 			}
 		]

src/cards/TRID4DWAVENX.conf

@@ -56,21 +56,21 @@ pcm.trid4dwavenx_rear {
 		hook_args [
 			{
 				name "Rear Path"
-				index &(subdevice)
+				index { @func private_pcm_subdevice }
 				lock true
 				preserve true
 				value true
 			}
 			{
 				name "PCM Front Playback Volume"
-				index &(subdevice)
+				index { @func private_pcm_subdevice }
 				lock true
 				preserve true
 				value [ 0 0 ]
 			}
 			{
 				name "PCM Reverb Playback Volume"
-				index &(subdevice)
+				index { @func private_pcm_subdevice }
 				lock true
 				preserve true
 				value [ 127 127 ]