media: sti/delta: remove uneeded check

At the error logic, ipc_buf was already asigned to &ctx->ipc_buf_struct,
with can't be null, as warned by smatch:

	drivers/media/platform/sti/delta/delta-ipc.c:223 delta_ipc_open() warn: variable dereferenced before check 'ctx->ipc_buf' (see line 183)

So, remove the uneeded check.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/sti/delta/delta-ipc.c

@@ -220,10 +220,8 @@ int delta_ipc_open(struct delta_ctx *pctx, const char *name,
 
 err:
 	pctx->sys_errors++;
-	if (ctx->ipc_buf) {
 	hw_free(pctx, ctx->ipc_buf);
 	ctx->ipc_buf = NULL;
-	}
 
 	return ret;
 };