powerpc: do not build ppc_save_regs.o always

The Fixes commit below tried to add CONFIG_PPC_BOOK3S to one of the
conditions to enable the build of ppc_save_regs.o. But it failed to do
so, in fact. The commit omitted to add a dollar sign.

Therefore, ppc_save_regs.o is built always these days (as
"(CONFIG_PPC_BOOK3S)" is never an empty string).

Fix this by adding the missing dollar sign.

Signed-off-by: Jiri Slaby (SUSE) <[email protected]>
Fixes: fc2a5a6 ("powerpc/64s: ppc_save_regs is now needed for all 64s builds")
Acked-by: Stephen Rothwell <[email protected]>
Signed-off-by: Madhavan Srinivasan <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: Jiri Slaby (SUSE)

arch/powerpc/kernel/Makefile

@@ -160,7 +160,7 @@ endif
 
 obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= tm.o
 
-ifneq ($(CONFIG_XMON)$(CONFIG_KEXEC_CORE)(CONFIG_PPC_BOOK3S),)
+ifneq ($(CONFIG_XMON)$(CONFIG_KEXEC_CORE)$(CONFIG_PPC_BOOK3S),)
 obj-y				+= ppc_save_regs.o
 endif