nasm.c: clean up pass exit logic
nasm.c: clean up pass exit logic

Clean up the pass exit logic.  In particular, we had a whole routine
to do the same thing that the normal exit logic would do anyway if we
only would actually get there.

Signed-off-by: H. Peter Anvin <8a453bad9912ffe59bc0f0b8abe03df9be19379e@zytor.com>

turingstudio/nasm,projedi/nasm,turingstudio/nasm,Distrotech/nasm,techkey/nasm,letolabs/nasm,letolabs/nasm,techkey/nasm,Distrotech/nasm,techkey/nasm,techkey/nasm,projedi/nasm,Distrotech/nasm,turingstudio/nasm,projedi/nasm,projedi/nasm,projedi/nasm,Distrotech/nasm,letolabs/nasm,techkey/nasm,turingstudio/nasm