powerpc/64s: Move SET_SCRATCH0() into EXCEPTION_RELON_PROLOG_PSERIES()

EXCEPTION_RELON_PROLOG_PSERIES() only has two users,
STD_RELON_EXCEPTION_PSERIES() and STD_RELON_EXCEPTION_HV() both of
which "call" SET_SCRATCH0(), so just move SET_SCRATCH0() into
EXCEPTION_RELON_PROLOG_PSERIES().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/exception-64s.h

@@ -183,6 +183,7 @@
  * case EXCEPTION_RELON_PROLOG_PSERIES_1 will be using lr.
  */
 #define EXCEPTION_RELON_PROLOG_PSERIES(area, label, h, extra, vec)	\
+	SET_SCRATCH0(r13);		/* save r13 */			\
 	EXCEPTION_PROLOG_0(area);					\
 	EXCEPTION_PROLOG_1(area, extra, vec);				\
 	EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)
@@ -576,7 +577,6 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 
 #define STD_RELON_EXCEPTION_PSERIES(loc, vec, label)	\
 	/* No guest interrupts come through here */	\
-	SET_SCRATCH0(r13);		/* save r13 */	\
 	EXCEPTION_RELON_PROLOG_PSERIES(PACA_EXGEN, label, EXC_STD, NOTEST, vec);
 
 #define STD_RELON_EXCEPTION_PSERIES_OOL(vec, label)		\
@@ -584,7 +584,6 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 	EXCEPTION_RELON_PROLOG_PSERIES_1(label, EXC_STD)
 
 #define STD_RELON_EXCEPTION_HV(loc, vec, label)		\
-	SET_SCRATCH0(r13);	/* save r13 */		\
 	EXCEPTION_RELON_PROLOG_PSERIES(PACA_EXGEN, label,	\
 				       EXC_HV, KVMTEST_HV, vec);