don't return NULL here.

libclamav/bytecode_api.c

@@ -351,7 +351,7 @@ uint8_t* cli_bcapi_malloc(struct cli_bc_ctx *ctx, uint32_t size)
 #else
     /* TODO: implement using a list of pointers we allocated! */
     cli_errmsg("cli_bcapi_malloc not implemented for systems without mmap yet!\n");
-    return NULL;
+    return cli_malloc(size);
 #endif
 }