powerpc/fadump: Correct two typos in a comment

Fix typos of 'remaining' and 'those'.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Suggested-by: Matthew Wilcox <willy@infradead.org> # 'remaining'
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211030002619.2063-1-rdunlap@infradead.org