nasmlib: Drop pure_func attrib from seg_alloc
nasmlib: Drop pure_func attrib from seg_alloc

It not only reads static variable but writes it back as well.

https://bugzilla.nasm.us/show_bug.cgi?id=3392461

Reported-by: Michael Šimáček <bb00374592417e6dd798bcd6018940f4a44e8fb0@redhat.com>
Signed-off-by: Cyrill Gorcunov <7a1ea01eee6961eb1e372e3508c2670446d086f4@gmail.com>

techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm