powerpc/64s/exception: fix line wrap and semicolon inconsistencies in macros

By convention, all lines should be separated by a semicolons. Last line
should have neither semicolon or line wrap.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>