[SPARC64]: Don't clobber alt-global %g4 on window fixups.

If we are returning back to kernel mode, %g4 could be live
(for example, in the case where we window spill in the etrap
code).  So do not change it's value if going back to kernel.

Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed