powerpc: Fix check for copy/paste instructions in alignment handler

powerpc: Fix check for copy/paste instructions in alignment handler

Commit 07d2a628bc00 ("powerpc/64s: Avoid cpabort in context switch
when possible", 2017-06-09) changed the definition of PPC_INST_COPY
and in so doing inadvertently broke the check for copy/paste
instructions in the alignment fault handler. The check currently
matches no instructions.

This fixes it by ANDing both sides of the comparison with the mask.

Fixes: 07d2a628bc00 ("powerpc/64s: Avoid cpabort in context switch when possible")
Cc: [email protected] # v4.13+
Reported-by: Markus Trippelsdorf <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>