powerpc/book3s64: fix dump_linuxpagetables "present" flag

Since commit bd0dbb73 ("powerpc/mm/books3s: Add new pte bit to
mark pte temporarily invalid."), _PAGE_PRESENT doesn't mean exactly
that a page is present. A page is also considered preset when
_PAGE_INVALID is set.

This patch changes the meaning of "present" and adds a status "valid"
associated to the _PAGE_PRESENT flag.

Fixes: bd0dbb73 ("powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid.")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/dump_linuxpagetables-book3s64.c

@@ -38,8 +38,13 @@ static const struct flag_info flag_array[] = {
 	}, {
 		.mask	= _PAGE_PRESENT,
 		.val	= _PAGE_PRESENT,
-		.set	= "present",
+		.set	= "valid",
 		.clear	= "     ",
+	}, {
+		.mask	= _PAGE_PRESENT | _PAGE_INVALID,
+		.val	= 0,
+		.set	= "       ",
+		.clear	= "present",
 	}, {
 		.mask	= H_PAGE_HASHPTE,
 		.val	= H_PAGE_HASHPTE,