ARM: 5740/1: fix valid_phys_addr_range() range check

Commit 1522ac3e
("Fix virtual to physical translation macro corner cases")
breaks the end of memory check in valid_phys_addr_range().
The modified expression results in the apparent /dev/mem size
being 2 bytes smaller than what it actually is.

This patch reworks the expression to correctly check the address,
while maintaining use of a valid address to __pa().
Signed-off-by: NGreg Ungerer <gerg@uclinux.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/mmap.c

@@ -124,7 +124,7 @@ int valid_phys_addr_range(unsigned long addr, size_t size)
 {
 	if (addr < PHYS_OFFSET)
 		return 0;
-	if (addr + size >= __pa(high_memory - 1))
+	if (addr + size > __pa(high_memory - 1) + 1)
 		return 0;
 
 	return 1;