This patch fixes corner case when (fp + 4) overflows unsigned long,
for example: fp = 0xFFFFFFFF -> fp + 4 == 3.
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>