powerpc/ptdump: drop dummy KERN_VIRT_START on PPC32

PPC32 doesn't have KERN_VIRT_START. Make PAGE_OFFSET the
default starting address for the dump, and drop the dummy
definition of KERN_VIRT_START. Only use KERN_VIRT_START for
non radix PPC64.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/334632b1df4775b0ccf3bdc8d6b201d14e3daedd.1565786091.git.christophe.leroy@c-s.fr

arch/powerpc/mm/ptdump/ptdump.c

@@ -26,10 +26,6 @@
 
 #include "ptdump.h"
 
-#ifdef CONFIG_PPC32
-#define KERN_VIRT_START	0
-#endif
-
 /*
  * To visualise what is happening,
  *
@@ -362,12 +358,13 @@ static int ptdump_show(struct seq_file *m, void *v)
 	struct pg_state st = {
 		.seq = m,
 		.marker = address_markers,
+		.start_address = PAGE_OFFSET,
 	};
 
-	if (radix_enabled())
-		st.start_address = PAGE_OFFSET;
-	else
+#ifdef CONFIG_PPC64
+	if (!radix_enabled())
 		st.start_address = KERN_VIRT_START;
+#endif
 
 	/* Traverse kernel page tables */
 	walk_pagetables(&st);
@@ -405,12 +402,13 @@ void ptdump_check_wx(void)
 		.seq = NULL,
 		.marker = address_markers,
 		.check_wx = true,
+		.start_address = PAGE_OFFSET,
 	};
 
-	if (radix_enabled())
-		st.start_address = PAGE_OFFSET;
-	else
+#ifdef CONFIG_PPC64
+	if (!radix_enabled())
 		st.start_address = KERN_VIRT_START;
+#endif
 
 	walk_pagetables(&st);