Since we have real bus error faults, and handle them as such, always treat uvm_fault() returning EACCES as a segmentation fault rather than a bus error, whatever address the fault is at.
Since we have real bus error faults, and handle them as such, always treat
uvm_fault() returning EACCES as a segmentation fault rather than a bus
error, whatever address the fault is at.

As a result, this correctly delivers SIGSEGV, rather than SIGBUS, when
attempting to write to a page with only PROT_READ permissions.

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars