powerpc/interrupt: Use names in check_return_regs_valid()

trap->regs == 0x3000 is trap_is_scv()

trap 0x500 is INTERRUPT_EXTERNAL
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d48bf0184a1de185eb0ed3282247f8a294710674.1624632537.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/interrupt.c

@@ -222,12 +222,12 @@ static void check_return_regs_valid(struct pt_regs *regs)
 	u8 *validp;
 	char *h;
 
-	if (regs->trap == 0x3000)
+	if (trap_is_scv(regs))
 		return;
 
 	trap = regs->trap;
 	// EE in HV mode sets HSRRs like 0xea0
-	if (cpu_has_feature(CPU_FTR_HVMODE) && trap == 0x500)
+	if (cpu_has_feature(CPU_FTR_HVMODE) && trap == INTERRUPT_EXTERNAL)
 		trap = 0xea0;
 
 	switch (trap) {