In commit 309376f51a, it seems like regression
was added to use ROM level API for disabling flash write protection. This
started random firmware crashes (on specific modules) with exception
`IllegalInstruction` during encrypted flash writes.
Fix here removes relevant ROM API call, since disabling flash write protection
is already ensured by caller of this API.
Closes https://github.com/espressif/esp-idf/issues/5467