UPSTREAM: erofs: fix an error code in z_erofs_init_zip_subsystem()

Return -ENOMEM if alloc_workqueue() fails.  Don't return success.

Fixes: d8a650adf429 ("erofs: add per-cpu threads for decompression as an option")
Bug: 271636421
Bug: 278520205
Tests: launch_cvd
Change-Id: I49dcf8094655db47ac71ae8967b5402373fc7adc
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/Y+4d0FRsUq8jPoOu@kili


Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
(cherry picked from commit 8d1b80a79452630f157bf634ae9cfcd9f4eed161)
Signed-off-by: Sandeep Dhavale <dhavale@google.com>
(cherry picked from commit 5004cc655730355d681b333ff5eafd62a4ee02f2)
(cherry picked from commit b7f5039f59d8bee886f584c65ca30f14be4b642c)