powerpc/fadump: Update comment about offset where fadump is reserved

With commit f6e6bedb7731 ("powerpc/fadump: Reserve memory at an offset
closer to bottom of RAM"), memory for fadump is no longer reserved at
the top of RAM. But there are still a few places which say so. Change
them appropriately.

Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 1bdbe0b..1ec6ea6 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -217,8 +217,8 @@ static inline unsigned long fadump_calculate_reserve_size(void)
 
 	/*
 	 * Check if the size is specified through crashkernel= cmdline
-	 * option. If yes, then use that but ignore base as fadump
-	 * reserves memory at end of RAM.
+	 * option. If yes, then use that but ignore base as fadump reserves
+	 * memory at a predefined offset.
 	 */
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 				&size, &base);