Remove FS_Read2().

Functionally the same as FS_Read().
Streaming functionality was removed in https://github.com/ioquake/ioq3/commit/672cfbf16f83fb67f6ce9bb1d3571dc32a5b3083 but flag remained.

code/client/cl_cgame.c

@@ -440,7 +440,7 @@ intptr_t CL_CgameSystemCalls( intptr_t *args ) {
 	case CG_FS_FOPENFILE:
 		return FS_FOpenFileByMode( VMA(1), VMA(2), args[3] );
 	case CG_FS_READ:
-		FS_Read2( VMA(1), args[2], args[3] );
+		FS_Read( VMA(1), args[2], args[3] );
 		return 0;
 	case CG_FS_WRITE:
 		FS_Write( VMA(1), args[2], args[3] );

code/client/cl_ui.c

@@ -780,7 +780,7 @@ intptr_t CL_UISystemCalls( intptr_t *args ) {
 		return FS_FOpenFileByMode( VMA(1), VMA(2), args[3] );
 
 	case UI_FS_READ:
-		FS_Read2( VMA(1), args[2], args[3] );
+		FS_Read( VMA(1), args[2], args[3] );
 		return 0;
 
 	case UI_FS_WRITE: